diff --git a/pages/buyer/index.js b/pages/buyer/index.js
index 6608e8a..ca2c941 100644
--- a/pages/buyer/index.js
+++ b/pages/buyer/index.js
@@ -1211,6 +1211,19 @@ Page({
 
   // 预览图片
   previewImage(e) {
+    // 登录验证
+    const userInfo = wx.getStorageSync('userInfo') || null
+    const userId = wx.getStorageSync('userId') || null
+    if (!userInfo || !userId) {
+      // 未登录，显示授权登录弹窗
+      this.setData({
+        showAuthModal: true,
+        pendingUserType: 'buyer'
+      })
+      return
+    }
+    
+    // 已登录，执行图片预览
     const { urls, index } = e.currentTarget.dataset
     this.setData({
       showImagePreview: true,
@@ -1221,6 +1234,19 @@ Page({
 
   // 预览图片
   previewImage(e) {
+    // 登录验证
+    const userInfo = wx.getStorageSync('userInfo') || null
+    const userId = wx.getStorageSync('userId') || null
+    if (!userInfo || !userId) {
+      // 未登录，显示授权登录弹窗
+      this.setData({
+        showAuthModal: true,
+        pendingUserType: 'buyer'
+      })
+      return
+    }
+    
+    // 已登录，执行图片预览
     const { urls, index } = e.currentTarget.dataset
     this.setData({
       showImagePreview: true,