diff --git a/src/__tests__/siteVisualAid.spec.ts b/src/__tests__/siteVisualAid.spec.ts
new file mode 100644
index 0000000..27c6cf3
--- /dev/null
+++ b/src/__tests__/siteVisualAid.spec.ts
@@ -0,0 +1,107 @@
+// @vitest-environment jsdom
+/**
+ * F5（docs/20）页脚/基础展示视觉位置示意：
+ * ① 页脚分组底部渲染 FooterPreview 结构示意图（六处位置标注，已填内容回显）；
+ * ② asset 字段的 aspect 占位框（favicon 1:1 / 二维码 4:3，无值虚线框、有值比例预览）。
+ */
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { createApp, defineComponent, h, nextTick, ref } from "vue";
+import ViewUIPlus from "view-ui-plus";
+
+vi.mock("@/api/module/cms", () => ({
+    assetUrl: (u: string) => u,
+    uploadUrl: () => "/api/attachment/upload",
+}));
+
+import SiteConfigForm from "@/views/cms/components/SiteConfigForm.vue";
+
+const cleanups: (() => void)[] = [];
+async function settle(frames = 4) {
+    for (let i = 0; i < frames; i++) {
+        await nextTick();
+    }
+    await new Promise(r => setTimeout(r, 0));
+    await nextTick();
+}
+
+const FOOTER_CONFIG = JSON.stringify({
+    contact: "电话 0571-88888888",
+    footer_addresses: "潭山校区：南湖路 237 号\n淮河校区：大学路 1 号",
+    qr_wechat: "/cms/upload/qr-wechat.png",
+    social_weibo: "https://weibo.com/xxx",
+    copyright: "XX学校 · 版权所有 © 2026",
+    beian: "浙ICP备XXXXXXXX号-1",
+    logo: "/cms/upload/logo.png",
+});
+
+async function mountForm(configJson: string, groups?: string[]) {
+    const el = document.createElement("div");
+    document.body.appendChild(el);
+    const model = ref(configJson);
+    const app = createApp(
+        defineComponent({
+            render: () =>
+                h(SiteConfigForm, {
+                    modelValue: model.value,
+                    groups,
+                    "onUpdate:modelValue": (v: string) => (model.value = v),
+                }),
+        }),
+    );
+    app.use(ViewUIPlus);
+    app.mount(el);
+    cleanups.push(() => {
+        app.unmount();
+        el.remove();
+    });
+    await settle();
+    return el;
+}
+
+afterEach(() => {
+    cleanups.splice(0).forEach(fn => fn());
+});
+
+describe("F5 视觉位置示意（docs/20）", () => {
+    it("页脚分组：底部渲染结构示意图，六处位置标注 + 已填内容回显", async () => {
+        const el = await mountForm(FOOTER_CONFIG, ["footer"]);
+        const preview = el.querySelector(".footer-preview")!;
+        expect(preview).toBeTruthy();
+        const text = preview.textContent || "";
+        // 已填字段实时回显内容（而非占位标注）
+        expect(text).toContain("电话 0571-88888888");
+        expect(text).toContain("潭山校区：南湖路 237 号");
+        expect(text).toContain("XX学校 · 版权所有 © 2026");
+        expect(text).toContain("浙ICP备XXXXXXXX号-1");
+        expect(preview.querySelector('img[src="/cms/upload/qr-wechat.png"]')).toBeTruthy();
+        // 未填字段显示位置标注（微博二维码空 → 占位）
+        expect(text).toContain("微博二维码");
+        expect(text).toContain("社媒图标行");
+    });
+
+    it("页脚全空配置：六处位置标注完整（① 联系方式/② 地址/③ 二维码/④ 社媒/⑤ 版权/⑥ 备案）", async () => {
+        const el = await mountForm("{}", ["footer"]);
+        const text = el.querySelector(".footer-preview")!.textContent || "";
+        expect(text).toContain("① 联系方式");
+        expect(text).toContain("② 多校区地址");
+        expect(text).toContain("微信二维码");
+        expect(text).toContain("③ 4:3");
+        expect(text).toContain("④ 社媒图标行");
+        expect(text).toContain("⑤ 版权文字");
+        expect(text).toContain("⑥ 备案号");
+    });
+
+    it("基础展示分组：无示意图（仅页脚有）", async () => {
+        const el = await mountForm(FOOTER_CONFIG, ["display"]);
+        expect(el.querySelector(".footer-preview")).toBeFalsy();
+    });
+
+    it("aspect 占位框：二维码无值时 4:3 虚线占位、favicon 无值时 1:1 占位", async () => {
+        const el = await mountForm("{}", ["display", "footer"]);
+        const holders = el.querySelectorAll(".iaf-holder");
+        expect(holders.length).toBe(3); // favicon 1:1 + 微信/微博 4:3
+        expect(el.querySelector(".iaf-holder-1x1")).toBeTruthy();
+        expect(el.querySelectorAll(".iaf-holder-4x3").length).toBe(2);
+        expect(holders[0].textContent).toContain("1:1");
+    });
+});
diff --git a/src/components/FooterPreview.vue b/src/components/FooterPreview.vue
new file mode 100644
index 0000000..ab2a752
--- /dev/null
+++ b/src/components/FooterPreview.vue
@@ -0,0 +1,171 @@
+<script setup lang="ts">
+import { assetUrl } from "@/api/module/cms";
+/**
+ * F5（docs/20）页脚结构示意图：页脚 Tab 内的固定示意图，标注各字段在门户页脚中的视觉位置——
+ * 品牌区（站名+联系方式+多校区地址行）/ 二维码区（微信+微博，4:3）/ 社媒图标行 / 版权备案行。
+ * 已填字段实时回显内容（填完即知页脚长什么样）；空字段以灰字占位标注。
+ */
+const props = defineProps<{
+    contact?: string;
+    footerAddresses?: string;
+    qrWechat?: string;
+    qrWeibo?: string;
+    socials?: { label: string; value?: string }[];
+    copyright?: string;
+    beian?: string;
+}>();
+
+const addressLines = (props.footerAddresses || "")
+    .split(/\r?\n/)
+    .map(l => l.trim())
+    .filter(Boolean)
+    .slice(0, 3);
+</script>
+
+<template>
+    <div class="footer-preview">
+        <div class="fp-caption">页脚结构示意（下图与字段一一对应，已填内容实时回显）</div>
+        <div class="fp-frame" role="img" aria-label="页脚结构示意图">
+            <div class="fp-brand">
+                <div class="fp-logo">
+                    <span class="fp-logo-mark">LOGO</span>
+                    <span class="fp-site">XX学校</span>
+                </div>
+                <p class="fp-line" :class="{ filled: contact }">
+                    {{ contact || "① 联系方式（页脚品牌区）" }}
+                </p>
+                <p v-for="(l, i) in addressLines" :key="i" class="fp-line small filled">{{ l }}</p>
+                <p v-if="!addressLines.length" class="fp-line small">② 多校区地址（每行一个校区）</p>
+            </div>
+            <div class="fp-qr">
+                <div class="fp-qr-box">
+                    <img v-if="qrWechat" :src="assetUrl(qrWechat)" alt="微信二维码预览" />
+                    <span v-else>微信二维码<br />③ 4:3</span>
+                </div>
+                <div class="fp-qr-box">
+                    <img v-if="qrWeibo" :src="assetUrl(qrWeibo)" alt="微博二维码预览" />
+                    <span v-else>微博二维码<br />③ 4:3</span>
+                </div>
+            </div>
+            <div class="fp-social">
+                <span class="fp-social-label">④ 社媒图标行：</span>
+                <span v-for="s in socials" :key="s.label" class="fp-social-item" :class="{ on: s.value }">
+                    {{ s.label }}
+                </span>
+            </div>
+            <div class="fp-bottom">
+                <span :class="{ filled: copyright }">{{ copyright || "⑤ 版权文字" }}</span>
+                <span :class="{ filled: beian }" class="fp-beian">{{ beian || "⑥ 备案号" }}</span>
+            </div>
+        </div>
+    </div>
+</template>
+
+<style scoped lang="scss">
+.footer-preview {
+    margin-top: 6px;
+    .fp-caption {
+        color: #8a93a6;
+        font-size: 12px;
+        margin-bottom: 8px;
+    }
+    .fp-frame {
+        border: 1px solid #e9edf5;
+        border-radius: 8px;
+        background: linear-gradient(180deg, #1f3a5f 0%, #16294a 100%);
+        color: rgba(255, 255, 255, 0.5);
+        padding: 18px 22px 12px;
+        display: grid;
+        grid-template-columns: 1fr auto;
+        gap: 10px 18px;
+        font-size: 12px;
+        line-height: 1.7;
+        .fp-brand {
+            .fp-logo {
+                display: flex;
+                align-items: center;
+                gap: 8px;
+                margin-bottom: 6px;
+                .fp-logo-mark {
+                    border: 1px dashed rgba(255, 255, 255, 0.35);
+                    border-radius: 4px;
+                    padding: 2px 8px;
+                    font-size: 11px;
+                }
+                .fp-site {
+                    color: rgba(255, 255, 255, 0.75);
+                    font-weight: 600;
+                }
+            }
+            .fp-line {
+                margin: 2px 0;
+                &.small {
+                    font-size: 11px;
+                    opacity: 0.9;
+                }
+                &.filled {
+                    color: #fff;
+                }
+            }
+        }
+        .fp-qr {
+            display: flex;
+            gap: 12px;
+            align-items: flex-start;
+            .fp-qr-box {
+                width: 84px;
+                height: 63px;
+                border: 1px dashed rgba(255, 255, 255, 0.4);
+                border-radius: 6px;
+                display: flex;
+                align-items: center;
+                justify-content: center;
+                text-align: center;
+                font-size: 10px;
+                position: relative;
+                overflow: hidden;
+                img {
+                    max-width: 100%;
+                    max-height: 100%;
+                    object-fit: contain;
+                }
+            }
+        }
+        .fp-social {
+            grid-column: 1 / -1;
+            display: flex;
+            align-items: center;
+            gap: 8px;
+            flex-wrap: wrap;
+            .fp-social-label {
+                color: rgba(255, 255, 255, 0.45);
+            }
+            .fp-social-item {
+                border: 1px solid rgba(255, 255, 255, 0.3);
+                border-radius: 12px;
+                padding: 1px 10px;
+                font-size: 11px;
+                opacity: 0.55;
+                &.on {
+                    opacity: 1;
+                    border-color: rgba(255, 255, 255, 0.85);
+                    color: #fff;
+                }
+            }
+        }
+        .fp-bottom {
+            grid-column: 1 / -1;
+            border-top: 1px solid rgba(255, 255, 255, 0.15);
+            padding-top: 8px;
+            display: flex;
+            justify-content: space-between;
+            gap: 12px;
+            flex-wrap: wrap;
+            font-size: 11px;
+            .filled {
+                color: rgba(255, 255, 255, 0.85);
+            }
+        }
+    }
+}
+</style>
diff --git a/src/components/ImageAssetField.vue b/src/components/ImageAssetField.vue
index 4ec27ad..d998ad6 100644
--- a/src/components/ImageAssetField.vue
+++ b/src/components/ImageAssetField.vue
@@ -15,6 +15,9 @@ const props = defineProps<{
     /** 附件场景（空=不带 scene；svc 场景已迁办事大厅，CMS 内为 article/banner 等） */
     scene?: string;
     placeholder?: string;
+    /** F5（docs/20）：预览/占位框比例（"1:1" favicon / "4:3" 二维码；缺省 8:5 通用横图），
+     *  无值时按比例显示虚线占位框，帮助确认最终在门户中的尺寸感 */
+    aspect?: "1:1" | "4:3";
 }>();
 const emit = defineEmits<{ (e: "update:modelValue", v: string): void }>();
 
@@ -76,12 +79,16 @@ function clearValue() {
             >
                 <Button size="small" icon="ios-cloud-upload-outline" :loading="uploading">上传图片</Button>
             </Upload>
-            <span v-else class="iaf-thumb">
+            <span v-else class="iaf-thumb" :class="aspect ? 'iaf-thumb-' + aspect.replace(':', 'x') : ''">
                 <img :src="previewSrc" alt="" />
                 <span class="iaf-thumb-del" title="清除" @click="clearValue">
                     <Icon type="ios-close" />
                 </span>
             </span>
+            <!-- F5：无值时按字段比例显示虚线占位框（尺寸感示意） -->
+            <span v-if="!modelValue && aspect" class="iaf-holder" :class="'iaf-holder-' + aspect!.replace(':', 'x')">
+                {{ aspect }} 位
+            </span>
             <Button size="small" type="text" class="iaf-toggle" @click="manualOpen = !manualOpen">
                 {{ manualOpen ? "收起" : "手动粘贴路径" }}
             </Button>
@@ -123,6 +130,16 @@ function clearValue() {
             border: 1px solid #dcdee2;
             background: #f8f8f9;
         }
+        &.iaf-thumb-1x1 img {
+            width: 48px;
+            height: 48px;
+            object-fit: contain;
+        }
+        &.iaf-thumb-4x3 img {
+            width: 88px;
+            height: 66px;
+            object-fit: contain;
+        }
         .iaf-thumb-del {
             position: absolute;
             top: -7px;
@@ -142,6 +159,24 @@ function clearValue() {
             display: block;
         }
     }
+    .iaf-holder {
+        display: inline-flex;
+        align-items: center;
+        justify-content: center;
+        border: 1px dashed #cfd8e6;
+        border-radius: 4px;
+        color: #b4bfce;
+        font-size: 11px;
+        background: #fafbfd;
+        &.iaf-holder-1x1 {
+            width: 48px;
+            height: 48px;
+        }
+        &.iaf-holder-4x3 {
+            width: 88px;
+            height: 66px;
+        }
+    }
     .iaf-manual {
         max-width: 420px;
         margin-top: 6px;
diff --git a/src/utils/siteConfigForm.ts b/src/utils/siteConfigForm.ts
index fe7dbc3..3351483 100644
--- a/src/utils/siteConfigForm.ts
+++ b/src/utils/siteConfigForm.ts
@@ -17,6 +17,8 @@ export interface SiteConfigFieldDef {
     multiline?: boolean;
     /** url: http(s) URL；host: 域名（不带协议）；asset: / 开头路径或 http(s) URL；text: 仅长度 */
     kind?: "text" | "url" | "host" | "asset";
+    /** F5（docs/20）：asset 类字段的预览/占位框比例（favicon 1:1、二维码 4:3） */
+    aspect?: "1:1" | "4:3";
     maxLength?: number;
 }
 
@@ -28,7 +30,7 @@ export const SITE_CONFIG_FIELD_DEFS: SiteConfigFieldDef[] = [
         tip: "门户顶栏与页脚品牌位展示；建议先在「附件管理」上传，复制路径填到这里。",
     },
     {
-        key: "favicon", label: "浏览器图标 favicon", group: "display", kind: "asset", maxLength: 500,
+        key: "favicon", label: "浏览器图标 favicon", group: "display", kind: "asset", maxLength: 500, aspect: "1:1",
         placeholder: "如 /yschcms/upload/…/favicon.png（留空用主题内置图标）",
         tip: "浏览器标签页与收藏夹的小图标，不显示在页面正文中。",
     },
@@ -52,12 +54,12 @@ export const SITE_CONFIG_FIELD_DEFS: SiteConfigFieldDef[] = [
         tip: "逐行展示在页脚品牌区旁；换行即分行（最多 500 字）。",
     },
     {
-        key: "qr_wechat", label: "微信二维码", group: "footer", kind: "asset", maxLength: 500,
+        key: "qr_wechat", label: "微信二维码", group: "footer", kind: "asset", maxLength: 500, aspect: "4:3",
         placeholder: "如 /yschcms/upload/…/qr-wechat.png（留空不展示）",
         tip: "页脚二维码，悬停放大预览；建议先在「附件管理」上传。",
     },
     {
-        key: "qr_weibo", label: "微博二维码", group: "footer", kind: "asset", maxLength: 500,
+        key: "qr_weibo", label: "微博二维码", group: "footer", kind: "asset", maxLength: 500, aspect: "4:3",
         placeholder: "如 /yschcms/upload/…/qr-weibo.png（留空不展示）",
         tip: "显示在页脚右侧二维码区，与微信二维码并排，悬停放大预览。",
     },
diff --git a/src/views/cms/components/SiteConfigForm.vue b/src/views/cms/components/SiteConfigForm.vue
index 20d5133..88e9ba9 100644
--- a/src/views/cms/components/SiteConfigForm.vue
+++ b/src/views/cms/components/SiteConfigForm.vue
@@ -11,6 +11,7 @@ import {
     validateFieldValue,
 } from "@/utils/siteConfigForm";
 import ImageAssetField from "@/components/ImageAssetField.vue";
+import FooterPreview from "@/components/FooterPreview.vue";
 
 /**
  * 站点配置结构化表单（docs/09 §3.1；docs/16 §3.3 分区作用域；docs/20 F6 扩展参数区退役）：
@@ -120,6 +121,7 @@ function defsOf(group: string): SiteConfigFieldDef[] {
                         v-model="formModel.fields[def.key]"
                         :site-id="siteId"
                         :placeholder="def.placeholder"
+                        :aspect="def.aspect"
                         @update:model-value="emitUp"
                     />
                     <Input
@@ -138,6 +140,22 @@ function defsOf(group: string): SiteConfigFieldDef[] {
                     />
                     <p v-if="def.tip" class="cfg-tip">{{ def.tip }}</p>
                 </FormItem>
+                <!-- F5（docs/20）：页脚分组底部固定结构示意图（字段↔视觉位置一一对应，实时回显） -->
+                <FooterPreview
+                    v-if="g.name === 'footer'"
+                    :contact="formModel.fields.contact"
+                    :footer-addresses="formModel.fields.footer_addresses"
+                    :qr-wechat="formModel.fields.qr_wechat"
+                    :qr-weibo="formModel.fields.qr_weibo"
+                    :socials="[
+                        { label: '微信', value: formModel.fields.social_wechat },
+                        { label: '微博', value: formModel.fields.social_weibo },
+                        { label: '抖音', value: formModel.fields.social_douyin },
+                        { label: 'B站', value: formModel.fields.social_bilibili },
+                    ]"
+                    :copyright="formModel.fields.copyright"
+                    :beian="formModel.fields.beian"
+                />
             </template>
         </Form>
     </div>