diff --git a/src/main/java/com/yunhai/userbase/model/application/ApplicationInfoRequest.java b/src/main/java/com/yunhai/userbase/model/application/ApplicationInfoRequest.java
index db3c4c0..3e0167b 100644
--- a/src/main/java/com/yunhai/userbase/model/application/ApplicationInfoRequest.java
+++ b/src/main/java/com/yunhai/userbase/model/application/ApplicationInfoRequest.java
@@ -36,18 +36,18 @@ public class ApplicationInfoRequest {
     private Integer categoryId;
 
     /**
-     * 技术标识（= projman app.name，如 notice），全库唯一，新增必填。<br>
-     * 编辑不强制（部分提交场景不回传则保持原值）；值域为引用键，改名须盘点引用。
+     * 技术标识（= projman app.name，如 notice），全库唯一，新增与编辑均必填。<br>
+     * 编辑必填（2026-09-28 拍板）：app_code 是应用身份锚点（消息 jump_app/服务目录键），不许置空；
+     * 存量 null 历史行不追溯，但编辑提交时必须补填。值域为引用键，改名须盘点引用。
      */
-    @NotBlank(groups = ValidationGroups.Create.class, message = "技术标识不能为空")
+    @NotBlank(groups = {ValidationGroups.Create.class, ValidationGroups.Update.class}, message = "技术标识不能为空")
     @Size(max = 32, message = "技术标识长度不能超过32")
     private String appCode;
 
     /**
-     * 应用性质：BASE=基石 / BUSINESS=业务，新增必填。<br>
-     * 编辑不强制（不回传则保持原值）；学校模式覆盖线不涉及本字段。
+     * 应用性质：BASE=基石 / BUSINESS=业务，新增与编辑均必填（2026-09-28 拍板，存量 null 行不追溯）。
      */
-    @NotBlank(groups = ValidationGroups.Create.class, message = "应用性质不能为空")
+    @NotBlank(groups = {ValidationGroups.Create.class, ValidationGroups.Update.class}, message = "应用性质不能为空")
     @Size(max = 16, message = "应用性质长度不能超过16")
     private String appNature;
 
diff --git a/src/test/java/com/yunhai/userbase/model/application/ApplicationInfoRequestValidationTest.java b/src/test/java/com/yunhai/userbase/model/application/ApplicationInfoRequestValidationTest.java
new file mode 100644
index 0000000..98c8410
--- /dev/null
+++ b/src/test/java/com/yunhai/userbase/model/application/ApplicationInfoRequestValidationTest.java
@@ -0,0 +1,83 @@
+package com.yunhai.userbase.model.application;
+
+import com.yunhai.userbase.common.validation.ValidationGroups;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import javax.validation.ConstraintViolation;
+import javax.validation.Validation;
+import javax.validation.Validator;
+import javax.validation.ValidatorFactory;
+import java.util.Set;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * app_code / app_nature 编辑必填校验组单测（消息方案 C5，2026-09-28 拍板：新增/编辑均必填，
+ * 存量 null 历史行不追溯）。Create 组此前已必填；本测试冻结 Update 组同口径——
+ * 编辑提交置空 → 校验失败；带值 → 通过。学校模式覆盖线由前端分支原样回传原值满足校验
+ * （后端 editAppForSchool 只读 name/desc/pcIcon，其余字段忽略）。
+ */
+@DisplayName("ApplicationInfoRequest - app_code/app_nature 新增与编辑均必填")
+class ApplicationInfoRequestValidationTest {
+
+    private static Validator validator;
+
+    @BeforeAll
+    static void setUp() {
+        ValidatorFactory factory = Validation.buildDefaultValidatorFactory();
+        validator = factory.getValidator();
+    }
+
+    private ApplicationInfoRequest validRequest() {
+        ApplicationInfoRequest request = new ApplicationInfoRequest();
+        request.setId(100011);
+        request.setName("流程中心");
+        request.setCategoryId(2);
+        request.setAppCode("flow-center");
+        request.setAppNature("BUSINESS");
+        return request;
+    }
+
+    private static boolean hasViolation(Set<ConstraintViolation<ApplicationInfoRequest>> violations, String field) {
+        return violations.stream().anyMatch(v -> v.getPropertyPath().toString().equals(field));
+    }
+
+    @Test
+    void edit_空appCode_校验失败() {
+        ApplicationInfoRequest request = validRequest();
+        request.setAppCode(" ");
+        Set<ConstraintViolation<ApplicationInfoRequest>> violations =
+                validator.validate(request, ValidationGroups.Update.class);
+        assertTrue(hasViolation(violations, "appCode"), "编辑时技术标识置空必须被 Update 组拦截");
+    }
+
+    @Test
+    void edit_空appNature_校验失败() {
+        ApplicationInfoRequest request = validRequest();
+        request.setAppNature(null);
+        Set<ConstraintViolation<ApplicationInfoRequest>> violations =
+                validator.validate(request, ValidationGroups.Update.class);
+        assertTrue(hasViolation(violations, "appNature"), "编辑时应用性质置空必须被 Update 组拦截");
+    }
+
+    @Test
+    void edit_带appCodeAppNature_通过() {
+        Set<ConstraintViolation<ApplicationInfoRequest>> violations =
+                validator.validate(validRequest(), ValidationGroups.Update.class);
+        assertFalse(hasViolation(violations, "appCode"));
+        assertFalse(hasViolation(violations, "appNature"));
+    }
+
+    @Test
+    void create_空appCode_校验失败_口径不变() {
+        ApplicationInfoRequest request = validRequest();
+        request.setId(null);
+        request.setAppCode(null);
+        Set<ConstraintViolation<ApplicationInfoRequest>> violations =
+                validator.validate(request, ValidationGroups.Create.class);
+        assertTrue(hasViolation(violations, "appCode"), "新增必填为既有口径，防回归");
+    }
+}