diff --git a/backend/services/collector_deployer.go b/backend/services/collector_deployer.go
index 582d247..959c96f 100644
--- a/backend/services/collector_deployer.go
+++ b/backend/services/collector_deployer.go
@@ -136,7 +136,7 @@ After=network-online.target
 Type=simple
 User=root
 Group=root
-ExecStart=/usr/local/bin/promtail -config.file=/etc/promtail/promtail.yaml -positions.enabled=true
+ExecStart=/usr/local/bin/promtail -config.file=/etc/promtail/promtail.yaml
 ExecReload=/bin/kill -HUP $MAINPID
 Restart=always
 RestartSec=10
@@ -155,12 +155,52 @@ WantedBy=multi-user.target
 		return fmt.Errorf("启动 Promtail 失败: %w", err)
 	}
 
+	// 必须校验服务真的起来了：
+	// 原来只判断 systemctl 命令有没有执行错误，结果 Promtail 因配置/参数错误
+	// 崩溃重启 40+ 次，平台仍然显示"采集器已部署"，用户以为采集是好的。
+	if err := waitServiceActive(ctx, client, "promtail", 20*time.Second); err != nil {
+		out, _, _ := client.Execute(ctx, "journalctl -u promtail -n 15 --no-pager 2>/dev/null | tail -15")
+		tail := strings.TrimSpace(out)
+		if tail == "" {
+			out, _, _ = client.Execute(ctx, "tail -10 /var/log/promtail.log 2>/dev/null")
+			tail = strings.TrimSpace(out)
+		}
+		return fmt.Errorf("Promtail 启动后未处于运行状态：%v\n最近日志：\n%s", err, truncateForMessage(tail, 900))
+	}
+
 	// 保存配置快照
 	d.collector.Config = conf
 	d.log("success", "Promtail 部署完成", "")
 	return nil
 }
 
+// waitServiceActive 轮询 systemctl is-active，直到 active 或超时。
+// Promtail 起不来时 systemctl restart 依然返回 0（只是排队拉起），
+// 所以必须自己查状态，否则会把"崩溃重启中"误报成部署成功。
+func waitServiceActive(ctx context.Context, client *SSHClient, service string, timeout time.Duration) error {
+	deadline := time.Now().Add(timeout)
+	var last string
+	for time.Now().Before(deadline) {
+		out, _, err := client.Execute(ctx, fmt.Sprintf("systemctl is-active %s 2>&1", service))
+		last = strings.TrimSpace(out)
+		if err == nil && last == "active" {
+			return nil
+		}
+		time.Sleep(2 * time.Second)
+	}
+	if last == "" {
+		last = "unknown"
+	}
+	return fmt.Errorf("%s 状态=%s", service, last)
+}
+
+func truncateForMessage(s string, max int) string {
+	if len(s) <= max {
+		return s
+	}
+	return s[:max] + "…"
+}
+
 func (d *CollectorDeployer) uninstallHost(ctx context.Context) error {
 	host := d.collector.Host
 	if host == nil {