diff --git a/backend/internal/service/antigravity_oauth_service.go b/backend/internal/service/antigravity_oauth_service.go
index 52293cd5..3850fa57 100644
--- a/backend/internal/service/antigravity_oauth_service.go
+++ b/backend/internal/service/antigravity_oauth_service.go
@@ -237,21 +237,60 @@ func (s *AntigravityOAuthService) RefreshAccountToken(ctx context.Context, accou
 		tokenInfo.Email = existingEmail
 	}
 
-	// 每次刷新都调用 LoadCodeAssist 获取 project_id
-	client := antigravity.NewClient(proxyURL)
-	loadResp, _, err := client.LoadCodeAssist(ctx, tokenInfo.AccessToken)
-	if err != nil || loadResp == nil || loadResp.CloudAICompanionProject == "" {
-		// LoadCodeAssist 失败或返回空，保留原有 project_id，标记缺失
-		existingProjectID := strings.TrimSpace(account.GetCredential("project_id"))
+	// 每次刷新都调用 LoadCodeAssist 获取 project_id，失败时重试
+	existingProjectID := strings.TrimSpace(account.GetCredential("project_id"))
+	projectID, loadErr := s.loadProjectIDWithRetry(ctx, tokenInfo.AccessToken, proxyURL, 3)
+
+	if loadErr != nil {
+		// LoadCodeAssist 失败，保留原有 project_id
 		tokenInfo.ProjectID = existingProjectID
-		tokenInfo.ProjectIDMissing = true
+		// 只有从未获取过 project_id 且本次也获取失败时，才标记为真正缺失
+		// 如果之前有 project_id，本次只是临时故障，不应标记为错误
+		if existingProjectID == "" {
+			tokenInfo.ProjectIDMissing = true
+		}
 	} else {
-		tokenInfo.ProjectID = loadResp.CloudAICompanionProject
+		tokenInfo.ProjectID = projectID
 	}
 
 	return tokenInfo, nil
 }
 
+// loadProjectIDWithRetry 带重试机制获取 project_id
+// 返回 project_id 和错误，失败时会重试指定次数
+func (s *AntigravityOAuthService) loadProjectIDWithRetry(ctx context.Context, accessToken, proxyURL string, maxRetries int) (string, error) {
+	var lastErr error
+
+	for attempt := 0; attempt <= maxRetries; attempt++ {
+		if attempt > 0 {
+			// 指数退避：1s, 2s, 4s
+			backoff := time.Duration(1<<uint(attempt-1)) * time.Second
+			if backoff > 8*time.Second {
+				backoff = 8 * time.Second
+			}
+			time.Sleep(backoff)
+		}
+
+		client := antigravity.NewClient(proxyURL)
+		loadResp, _, err := client.LoadCodeAssist(ctx, accessToken)
+
+		if err == nil && loadResp != nil && loadResp.CloudAICompanionProject != "" {
+			return loadResp.CloudAICompanionProject, nil
+		}
+
+		// 记录错误
+		if err != nil {
+			lastErr = err
+		} else if loadResp == nil {
+			lastErr = fmt.Errorf("LoadCodeAssist 返回空响应")
+		} else {
+			lastErr = fmt.Errorf("LoadCodeAssist 返回空 project_id")
+		}
+	}
+
+	return "", fmt.Errorf("获取 project_id 失败 (重试 %d 次后): %w", maxRetries, lastErr)
+}
+
 // BuildAccountCredentials 构建账户凭证
 func (s *AntigravityOAuthService) BuildAccountCredentials(tokenInfo *AntigravityTokenInfo) map[string]any {
 	creds := map[string]any{
diff --git a/backend/internal/service/antigravity_token_refresher.go b/backend/internal/service/antigravity_token_refresher.go
index a07c86e6..2beb9e84 100644
--- a/backend/internal/service/antigravity_token_refresher.go
+++ b/backend/internal/service/antigravity_token_refresher.go
@@ -3,6 +3,7 @@ package service
 import (
 	"context"
 	"fmt"
+	"log"
 	"time"
 )
 
@@ -61,9 +62,17 @@ func (r *AntigravityTokenRefresher) Refresh(ctx context.Context, account *Accoun
 		}
 	}
 
-	// 如果 project_id 获取失败，返回 credentials 但同时返回错误让账户被标记
+	// 如果 project_id 获取失败但之前有 project_id，不返回错误（只是临时网络故障）
+	// 只有真正缺失 project_id（从未获取过）时才返回错误
 	if tokenInfo.ProjectIDMissing {
-		return newCredentials, fmt.Errorf("missing_project_id: 账户缺少project id，可能无法使用Antigravity")
+		// 检查是否保留了旧的 project_id
+		if tokenInfo.ProjectID != "" {
+			// 有旧的 project_id，只是本次获取失败，记录警告但不返回错误
+			log.Printf("[AntigravityTokenRefresher] Account %d: LoadCodeAssist 临时失败，保留旧 project_id", account.ID)
+		} else {
+			// 真正缺失 project_id，返回错误
+			return newCredentials, fmt.Errorf("missing_project_id: 账户缺少project id，可能无法使用Antigravity")
+		}
 	}
 
 	return newCredentials, nil
diff --git a/backend/internal/service/token_refresh_service.go b/backend/internal/service/token_refresh_service.go
index 7364bd33..6ef92bbf 100644
--- a/backend/internal/service/token_refresh_service.go
+++ b/backend/internal/service/token_refresh_service.go
@@ -237,7 +237,8 @@ func (s *TokenRefreshService) refreshWithRetry(ctx context.Context, account *Acc
 }
 
 // isNonRetryableRefreshError 判断是否为不可重试的刷新错误
-// 这些错误通常表示凭证已失效，需要用户重新授权
+// 这些错误通常表示凭证已失效或配置确实缺失，需要用户重新授权
+// 注意：missing_project_id 错误只在真正缺失（从未获取过）时返回，临时获取失败不会返回此错误
 func isNonRetryableRefreshError(err error) bool {
 	if err == nil {
 		return false