diff --git a/internal/config/defaults.go b/internal/config/defaults.go
index 2899a94..fc25a5e 100644
--- a/internal/config/defaults.go
+++ b/internal/config/defaults.go
@@ -409,6 +409,8 @@ func GenerateConfigYAML(cfg *Config) ([]byte, error) {
 	buf.WriteString("    #       cache_lock: true          # 防止缓存击穿\n")
 	buf.WriteString("    #       cache_lock_timeout: 5s   # 缓存锁超时时间（默认 5s）\n")
 	buf.WriteString("    #       stale_while_revalidate: 30s\n")
+	buf.WriteString("    #       stale_if_error: 1m       # 上游错误时使用过期缓存的时间窗口\n")
+	buf.WriteString("    #       stale_if_timeout: 30s    # 上游超时时使用过期缓存的时间窗口\n")
 	buf.WriteString("    #       background_update_disable: false  # 禁用后台更新（默认启用）\n")
 	buf.WriteString("    #       cache_ignore_headers: [] # 缓存时忽略的响应头\n")
 	buf.WriteString("    #       revalidate: false        # 启用条件请求（默认关闭）\n")
diff --git a/internal/proxy/proxy.go b/internal/proxy/proxy.go
index b172f09..06eefc8 100644
--- a/internal/proxy/proxy.go
+++ b/internal/proxy/proxy.go
@@ -181,7 +181,7 @@ func NewProxy(cfg *config.ProxyConfig, targets []*loadbalance.Target, transportC
 				MaxAge:   cfg.Cache.MaxAge,
 			})
 		}
-		p.cache = cache.NewProxyCache(rules, cfg.Cache.CacheLock, cfg.Cache.StaleWhileRevalidate)
+		p.cache = cache.NewProxyCache(rules, cfg.Cache.CacheLock, cfg.Cache.StaleWhileRevalidate, cfg.Cache.StaleIfError, cfg.Cache.StaleIfTimeout)
 	}
 
 	// 初始化重定向改写器
@@ -683,6 +683,19 @@ func (p *Proxy) ServeHTTP(ctx *fasthttp.RequestCtx) {
 				p.healthChecker.MarkUnhealthy(target)
 			}
 
+			// 尝试使用 stale 缓存
+			if p.cache != nil {
+				hashKey, origKey := p.buildCacheKeyHash(ctx)
+				isTimeout := errors.Is(err, fasthttp.ErrTimeout)
+				if staleEntry, ok := p.cache.GetStale(hashKey, origKey, isTimeout); ok {
+					logging.Info().Msgf("[PROXY] 使用 stale 缓存: key=%s, isTimeout=%v", origKey, isTimeout)
+					p.writeCachedResponse(ctx, staleEntry)
+					upstreamStatus = staleEntry.Status
+					upstreamAddr = upstreamCache
+					return
+				}
+			}
+
 			// 释放缓存锁
 			if p.cache != nil && attempt == 0 {
 				hashKey := p.buildCacheKeyHashValue(ctx)