diff --git a/cmd/relay_check.go b/cmd/relay_check.go
new file mode 100644
index 0000000..56be639
--- /dev/null
+++ b/cmd/relay_check.go
@@ -0,0 +1,111 @@
+package cmd
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"text/tabwriter"
+
+	"github.com/qingchencloud/cftunnel/internal/config"
+	"github.com/qingchencloud/cftunnel/internal/relay"
+	"github.com/spf13/cobra"
+)
+
+var checkJSON bool
+
+func init() {
+	relayCheckCmd.Flags().BoolVar(&checkJSON, "json", false, "JSON 格式输出")
+	relayCmd.AddCommand(relayCheckCmd)
+}
+
+var relayCheckCmd = &cobra.Command{
+	Use:   "check [规则名]",
+	Short: "检测中继链路连通性",
+	Long:  "检测 frps 服务器、本地服务、远程穿透端口的连通性和延迟。不指定规则名则检测全部规则。",
+	Args:  cobra.MaximumNArgs(1),
+	RunE: func(cmd *cobra.Command, args []string) error {
+		cfg, err := config.Load()
+		if err != nil {
+			return err
+		}
+		if cfg.Relay.Server == "" {
+			return fmt.Errorf("未配置中继服务器，请先执行 cftunnel relay init")
+		}
+
+		ruleName := ""
+		if len(args) > 0 {
+			ruleName = args[0]
+		}
+
+		result := relay.Check(&cfg.Relay, ruleName)
+
+		if checkJSON {
+			return printCheckJSON(result)
+		}
+		printCheckTable(result)
+		return nil
+	},
+}
+
+func printCheckTable(r relay.CheckResult) {
+	fmt.Println("中继链路检测")
+	fmt.Println("============")
+
+	// 服务器状态
+	if r.ServerOK {
+		fmt.Printf("服务器: %s  ✓ 可达 (%dms)\n", r.Server, r.ServerLatency)
+	} else {
+		fmt.Printf("服务器: %s  ✗ 不可达\n", r.Server)
+	}
+
+	// frpc 进程状态
+	if r.FrpcRunning {
+		fmt.Printf("frpc:   运行中 (PID: %d)\n", r.FrpcPID)
+	} else {
+		fmt.Println("frpc:   未运行")
+	}
+	fmt.Println()
+
+	if len(r.Rules) == 0 {
+		fmt.Println("暂无规则需要检测")
+		return
+	}
+
+	// 规则检测结果表格
+	w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
+	fmt.Fprintln(w, "规则\t协议\t本地端口\t远程端口\t本地服务\t远程穿透\t延迟")
+	fmt.Fprintln(w, "----\t----\t--------\t--------\t--------\t--------\t----")
+	for _, rule := range r.Rules {
+		local := "✓"
+		if !rule.LocalOK {
+			local = "✗ " + rule.LocalErr
+		}
+		remote := "-"
+		if rule.RemotePort > 0 {
+			if rule.RemoteOK {
+				remote = "✓"
+			} else {
+				remote = "✗ " + rule.RemoteErr
+			}
+		}
+		latency := "-"
+		if rule.LatencyMS > 0 {
+			latency = fmt.Sprintf("%dms", rule.LatencyMS)
+		}
+		remotePort := "-"
+		if rule.RemotePort > 0 {
+			remotePort = fmt.Sprintf("%d", rule.RemotePort)
+		}
+		fmt.Fprintf(w, "%s\t%s\t%d\t%s\t%s\t%s\t%s\n",
+			rule.Name, rule.Proto, rule.LocalPort, remotePort, local, remote, latency)
+	}
+	w.Flush()
+
+	fmt.Printf("\n结果: %d 条规则, %d 通 / %d 断\n", r.Total, r.Passed, r.Failed)
+}
+
+func printCheckJSON(r relay.CheckResult) error {
+	enc := json.NewEncoder(os.Stdout)
+	enc.SetIndent("", "  ")
+	return enc.Encode(r)
+}
diff --git a/internal/relay/check.go b/internal/relay/check.go
new file mode 100644
index 0000000..ca11eb5
--- /dev/null
+++ b/internal/relay/check.go
@@ -0,0 +1,135 @@
+package relay
+
+import (
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/qingchencloud/cftunnel/internal/config"
+)
+
+const checkTimeout = 3 * time.Second
+
+// CheckResult 链路检测总结果
+type CheckResult struct {
+	Server        string            `json:"server"`
+	ServerOK      bool              `json:"server_ok"`
+	ServerLatency int64             `json:"server_latency_ms"`
+	FrpcRunning   bool              `json:"frpc_running"`
+	FrpcPID       int               `json:"frpc_pid"`
+	Rules         []RuleCheckResult `json:"rules"`
+	Total         int               `json:"total"`
+	Passed        int               `json:"passed"`
+	Failed        int               `json:"failed"`
+}
+
+// RuleCheckResult 单条规则检测结果
+type RuleCheckResult struct {
+	Name       string `json:"name"`
+	Proto      string `json:"proto"`
+	LocalPort  int    `json:"local_port"`
+	RemotePort int    `json:"remote_port"`
+	LocalOK    bool   `json:"local_ok"`
+	RemoteOK   bool   `json:"remote_ok"`
+	LatencyMS  int64  `json:"latency_ms"`
+	LocalErr   string `json:"local_err,omitempty"`
+	RemoteErr  string `json:"remote_err,omitempty"`
+}
+
+// Check 执行链路检测
+func Check(cfg *config.RelayConfig, ruleName string) CheckResult {
+	result := CheckResult{Server: cfg.Server}
+
+	// 检测 frps 服务器连通性
+	if cfg.Server != "" {
+		start := time.Now()
+		conn, err := net.DialTimeout("tcp", cfg.Server, checkTimeout)
+		if err == nil {
+			conn.Close()
+			result.ServerOK = true
+			result.ServerLatency = time.Since(start).Milliseconds()
+		}
+	}
+
+	// 检测 frpc 进程
+	result.FrpcRunning = Running()
+	result.FrpcPID = PID()
+
+	// 筛选要检测的规则
+	rules := cfg.Rules
+	if ruleName != "" {
+		rules = nil
+		for _, r := range cfg.Rules {
+			if r.Name == ruleName {
+				rules = append(rules, r)
+				break
+			}
+		}
+	}
+
+	// 并行检测所有规则
+	result.Rules = make([]RuleCheckResult, len(rules))
+	var wg sync.WaitGroup
+	for i, rule := range rules {
+		wg.Add(1)
+		go func(idx int, r config.RelayRule) {
+			defer wg.Done()
+			result.Rules[idx] = checkRule(r, cfg.Server)
+		}(i, rule)
+	}
+	wg.Wait()
+
+	// 统计
+	result.Total = len(result.Rules)
+	for _, r := range result.Rules {
+		if r.LocalOK && (r.RemoteOK || r.RemotePort == 0) {
+			result.Passed++
+		} else {
+			result.Failed++
+		}
+	}
+	return result
+}
+
+// checkRule 检测单条规则
+func checkRule(r config.RelayRule, server string) RuleCheckResult {
+	rc := RuleCheckResult{
+		Name:       r.Name,
+		Proto:      r.Proto,
+		LocalPort:  r.LocalPort,
+		RemotePort: r.RemotePort,
+	}
+
+	localIP := r.LocalIP
+	if localIP == "" {
+		localIP = "127.0.0.1"
+	}
+
+	// 检测本地服务
+	localAddr := fmt.Sprintf("%s:%d", localIP, r.LocalPort)
+	conn, err := net.DialTimeout("tcp", localAddr, checkTimeout)
+	if err == nil {
+		conn.Close()
+		rc.LocalOK = true
+	} else {
+		rc.LocalErr = "未监听"
+	}
+
+	// 检测远程穿透端口
+	if r.RemotePort > 0 && server != "" {
+		host, _, _ := net.SplitHostPort(server)
+		remoteAddr := fmt.Sprintf("%s:%d", host, r.RemotePort)
+		start := time.Now()
+		conn, err := net.DialTimeout("tcp", remoteAddr, checkTimeout)
+		if err == nil {
+			conn.Close()
+			rc.RemoteOK = true
+			rc.LatencyMS = time.Since(start).Milliseconds()
+		} else {
+			rc.RemoteErr = "超时"
+		}
+	}
+
+	return rc
+}