diff --git a/backend/src/main/java/com/designhub/service/UserService.java b/backend/src/main/java/com/designhub/service/UserService.java
index 1befdfa..c23221a 100644
--- a/backend/src/main/java/com/designhub/service/UserService.java
+++ b/backend/src/main/java/com/designhub/service/UserService.java
@@ -610,23 +610,45 @@ public class UserService {
                     log.info("自动匹配到系统部门: deptId={}, deptName={}, type={}", 
                             matchedDeptId, dept.getDeptName(), dept.getDeptType());
                 } else {
-                    // 无法自动匹配，需要用户手动选择
-                    String deptNamesStr = dingDepartments.stream()
-                            .map(d -> String.valueOf(d.get("name")))
-                            .collect(Collectors.joining(", "));
-                    log.warn("无法自动匹配系统部门，钉钉部门: {}", deptNamesStr);
-                    user.setDeptId(null);
-                    user.setDeptName(null);
-                    user.setRoleIds(null);
-                    user.setStatus(0); // 暂时禁用，待选择部门后启用
+                    // 无法自动匹配，使用第一个可用部门作为默认值
+                    List<Department> availableDepts = departmentMapper.selectList(
+                        new LambdaQueryWrapper<Department>()
+                            .eq(Department::getStatus, 1)
+                            .eq(Department::getDeleted, 0)
+                            .orderByAsc(Department::getSortOrder)
+                            .orderByAsc(Department::getId)
+                    );
+                    
+                    if (!availableDepts.isEmpty()) {
+                        // 使用第一个可用部门作为默认值
+                        Department defaultDept = availableDepts.get(0);
+                        user.setDeptId(defaultDept.getId());
+                        user.setDeptName(defaultDept.getDeptName());
+                        user.setRoleIds("receiving".equals(defaultDept.getDeptType()) ? "5" : "6");
+                        log.warn("无法自动匹配系统部门，使用默认部门: deptId={}, deptName={}, 钉钉部门: {}", 
+                                defaultDept.getId(), defaultDept.getDeptName(),
+                                dingDepartments.stream()
+                                    .map(d -> String.valueOf(d.get("name")))
+                                    .collect(Collectors.joining(", ")));
+                    } else {
+                        // 如果系统没有任何部门，才需要用户手动选择
+                        String deptNamesStr = dingDepartments.stream()
+                                .map(d -> String.valueOf(d.get("name")))
+                                .collect(Collectors.joining(", "));
+                        log.warn("无法自动匹配系统部门，且系统无可用部门，钉钉部门: {}", deptNamesStr);
+                        user.setDeptId(null);
+                        user.setDeptName(null);
+                        user.setRoleIds(null);
+                        user.setStatus(0); // 暂时禁用，待选择部门后启用
+                    }
                 }
                 
                 userMapper.insert(user);
                 log.info("钉钉用户创建成功: userId={}, username={}, needSelectDept={}", 
                         user.getId(), user.getUsername(), matchedDeptId == null);
                 
-                // 如果需要选择部门，抛出特殊异常
-                if (matchedDeptId == null) {
+                // 如果需要选择部门（系统无任何可用部门的情况），抛出特殊异常
+                if (user.getDeptId() == null) {
                     String deptInfo = dingDepartments.isEmpty() ? "无钉钉部门信息" : 
                             dingDepartments.stream()
                                 .map(d -> String.valueOf(d.get("name")))
diff --git a/frontend/src/views/Login.vue b/frontend/src/views/Login.vue
index 10d8bff..49106a2 100644
--- a/frontend/src/views/Login.vue
+++ b/frontend/src/views/Login.vue
@@ -198,12 +198,12 @@
             @click="handleDingTalkLogin"
             :loading="dingTalkLoginLoading"
           >
-            <!-- 钉钉logo - 白色圆形带内部图形 -->
-            <svg class="dingtalk-logo" viewBox="0 0 64 64" width="20" height="20" fill="currentColor" xmlns="http://www.w3.org/2000/svg">
-              <circle cx="32" cy="32" r="28" fill="currentColor"/>
-              <circle cx="32" cy="32" r="24" fill="none" stroke="white" stroke-width="2"/>
-              <circle cx="32" cy="24" r="3" fill="white"/>
-              <rect x="29" y="30" width="6" height="8" rx="1" fill="white"/>
+            <!-- 钉钉官方logo SVG - 使用白色版本 -->
+            <svg class="dingtalk-logo" viewBox="0 0 1024 1024" width="20" height="20" xmlns="http://www.w3.org/2000/svg">
+              <path
+                d="M512 2C230.2 2 2 230.2 2 512s228.2 510 510 510 510-228.2 510-510S793.3 2 512 2z m235.9 442c-1 4.6-3.6 10.8-7.2 19.1l-0.5 0.5c-21.6 45.8-77.3 135.5-77.3 135.5l-0.5-0.5-16.5 28.3h78.8L574.3 826.8l34-136h-61.8l21.6-90.2c-17.5 4.1-38.1 9.8-62.3 18 0 0-33 19.1-94.8-37.1 0 0-41.7-37.1-17.5-45.8 10.3-4.1 50-8.8 81.4-12.9 42.2-5.7 68.5-8.8 68.5-8.8s-130.3 2.1-161.2-3.1c-30.9-4.6-70.1-56.7-78.3-102 0 0-12.9-24.7 27.8-12.9 40.2 11.8 209.2 45.8 209.2 45.8S321.4 375 307 358.5c-14.4-16.5-42.8-89.6-39.2-134.5 0 0 1.5-11.3 12.9-8.2 0 0 161.8 74.2 272.5 114.4C664.5 371.4 760.8 392 747.9 444z"
+                fill="currentColor"
+              />
             </svg>
             钉钉登录
           </a-button>