diff --git a/server/HoneyBox/src/HoneyBox.Core/Services/WechatService.cs b/server/HoneyBox/src/HoneyBox.Core/Services/WechatService.cs
index e7a61a11..be13b692 100644
--- a/server/HoneyBox/src/HoneyBox.Core/Services/WechatService.cs
+++ b/server/HoneyBox/src/HoneyBox.Core/Services/WechatService.cs
@@ -178,11 +178,29 @@ public class WechatService : IWechatService
 
         try
         {
-            var url = $"{WechatGetPhoneNumberUrl}?access_token={code}";
+            // 1. 先获取 access_token
+            var accessToken = await GetAccessTokenAsync();
+            if (string.IsNullOrEmpty(accessToken))
+            {
+                _logger.LogError("Failed to get access_token for phone number API");
+                return new WechatMobileResult
+                {
+                    Success = false,
+                    ErrorMessage = "获取access_token失败"
+                };
+            }
+
+            // 2. 使用 access_token 作为 URL 参数，code 放在请求体中
+            var url = $"{WechatGetPhoneNumberUrl}?access_token={accessToken}";
+            var requestBody = new { code = code };
+            var jsonContent = new StringContent(
+                JsonSerializer.Serialize(requestBody),
+                System.Text.Encoding.UTF8,
+                "application/json");
             
-            _logger.LogInformation("Calling WeChat API to get phone number");
+            _logger.LogInformation("Calling WeChat API to get phone number with access_token");
             
-            var response = await _httpClient.PostAsync(url, null);
+            var response = await _httpClient.PostAsync(url, jsonContent);
             var content = await response.Content.ReadAsStringAsync();
 
             if (!response.IsSuccessStatusCode)