diff --git a/internal/checkpool.go b/internal/checkpool.go
index acacb5d..406803b 100644
--- a/internal/checkpool.go
+++ b/internal/checkpool.go
@@ -30,7 +30,7 @@ func NewCheckPool(ctx context.Context, config *pkg.Config) (*CheckPool, error) {
 		reqCount:    1,
 		failedCount: 1,
 	}
-
+	pool.Headers = map[string]string{"Connection": "close"}
 	p, _ := ants.NewPoolWithFunc(config.Thread, pool.Invoke)
 
 	pool.pool = p
@@ -124,7 +124,7 @@ func (pool *CheckPool) Invoke(v interface{}) {
 	if err != nil {
 		logs.Log.Error(err.Error())
 	}
-
+	req.SetHeaders(pool.Headers)
 	start := time.Now()
 	var bl *pkg.Baseline
 	resp, reqerr := pool.client.Do(pool.ctx, req)
@@ -144,7 +144,13 @@ func (pool *CheckPool) Invoke(v interface{}) {
 				ReqDepth:  unit.depth,
 			},
 		}
-		pool.doUpgrade(bl)
+
+		if strings.Contains(reqerr.Error(), "timed out") || strings.Contains(reqerr.Error(), "actively refused") {
+
+		} else {
+			pool.doUpgrade(bl)
+		}
+
 	} else {
 		bl = pkg.NewBaseline(req.URI(), req.Host(), resp)
 		bl.Collect()
@@ -162,7 +168,12 @@ func (pool *CheckPool) Invoke(v interface{}) {
 			pool.doUpgrade(bl)
 			pool.FuzzyCh <- bl
 		} else {
-			pool.OutputCh <- bl
+			params := map[string]interface{}{
+				"current": bl,
+			}
+			if pool.MatchExpr == nil || CompareWithExpr(pool.MatchExpr, params) {
+				pool.OutputCh <- bl
+			}
 		}
 	}
 
diff --git a/internal/pool.go b/internal/pool.go
index f8015d6..8301227 100644
--- a/internal/pool.go
+++ b/internal/pool.go
@@ -3,8 +3,6 @@ package internal
 import (
 	"context"
 	"fmt"
-	"github.com/antonmedv/expr"
-	"github.com/antonmedv/expr/vm"
 	"github.com/chainreactors/logs"
 	"github.com/chainreactors/parsers"
 	"github.com/chainreactors/parsers/iutils"
@@ -561,19 +559,6 @@ func (pool *Pool) BaseCompare(bl *pkg.Baseline) bool {
 	return true
 }
 
-func CompareWithExpr(exp *vm.Program, params map[string]interface{}) bool {
-	res, err := expr.Run(exp, params)
-	if err != nil {
-		logs.Log.Warn(err.Error())
-	}
-
-	if res == true {
-		return true
-	} else {
-		return false
-	}
-}
-
 func (pool *Pool) Upgrade(bl *pkg.Baseline) error {
 	rurl, err := url.Parse(bl.RedirectURL)
 	if err == nil && rurl.Hostname() == bl.Url.Hostname() && bl.Url.Scheme == "http" && rurl.Scheme == "https" {
diff --git a/internal/utils.go b/internal/utils.go
index 7626cc9..85f247e 100644
--- a/internal/utils.go
+++ b/internal/utils.go
@@ -2,6 +2,9 @@ package internal
 
 import (
 	"bytes"
+	"github.com/antonmedv/expr"
+	"github.com/antonmedv/expr/vm"
+	"github.com/chainreactors/logs"
 	"github.com/chainreactors/spray/pkg"
 	"github.com/chainreactors/words/mask"
 	"github.com/chainreactors/words/rule"
@@ -249,3 +252,16 @@ func FormatURL(base, u string) string {
 func RandomUA() string {
 	return randomUserAgent[rand.Intn(uacount)]
 }
+
+func CompareWithExpr(exp *vm.Program, params map[string]interface{}) bool {
+	res, err := expr.Run(exp, params)
+	if err != nil {
+		logs.Log.Warn(err.Error())
+	}
+
+	if res == true {
+		return true
+	} else {
+		return false
+	}
+}
diff --git a/pkg/ihttp/client.go b/pkg/ihttp/client.go
index 6b7c100..05b3cae 100644
--- a/pkg/ihttp/client.go
+++ b/pkg/ihttp/client.go
@@ -75,9 +75,9 @@ type Client struct {
 
 func (c *Client) TransToCheck() {
 	if c.fastClient != nil {
-		c.fastClient.MaxConnsPerHost = 1
+		c.fastClient.MaxConnsPerHost = -1 // disable keepalive
 	} else if c.standardClient != nil {
-
+		c.standardClient.Transport.(*http.Transport).DisableKeepAlives = true // disable keepalive
 	}
 }