diff --git a/controllers/ldap.go b/controllers/ldap.go
index b2ae5a743b2a..cd15eb6887e9 100644
--- a/controllers/ldap.go
+++ b/controllers/ldap.go
@@ -59,6 +59,7 @@ func (c *ApiController) GetLdapUsers() {
 		c.ResponseError(err.Error())
 		return
 	}
+	defer conn.Close()
 
 	//groupsMap, err := conn.GetLdapGroups(ldapServer.BaseDn)
 	//if err != nil {
diff --git a/object/check.go b/object/check.go
index a6cc2638a3a4..6474e10c33e2 100644
--- a/object/check.go
+++ b/object/check.go
@@ -237,22 +237,28 @@ func checkLdapUserPassword(user *User, password string, lang string) error {
 
 		searchResult, err := conn.Conn.Search(searchReq)
 		if err != nil {
+			conn.Close()
 			return err
 		}
 
 		if len(searchResult.Entries) == 0 {
+			conn.Close()
 			continue
 		}
 		if len(searchResult.Entries) > 1 {
+			conn.Close()
 			return fmt.Errorf(i18n.Translate(lang, "check:Multiple accounts with same uid, please check your ldap server"))
 		}
 
 		hit = true
 		dn := searchResult.Entries[0].DN
-		if err := conn.Conn.Bind(dn, password); err == nil {
+		if err = conn.Conn.Bind(dn, password); err == nil {
 			ldapLoginSuccess = true
+			conn.Close()
 			break
 		}
+
+		conn.Close()
 	}
 
 	if !ldapLoginSuccess {
diff --git a/object/ldap_autosync.go b/object/ldap_autosync.go
index ceac2c18a228..8c80a8dc1dbb 100644
--- a/object/ldap_autosync.go
+++ b/object/ldap_autosync.go
@@ -100,6 +100,7 @@ func (l *LdapAutoSynchronizer) syncRoutine(ldap *Ldap, stopChan chan struct{}) e
 
 		users, err := conn.GetLdapUsers(ldap)
 		if err != nil {
+			conn.Close()
 			logs.Warning(fmt.Sprintf("autoSync failed for %s, error %s", ldap.Id, err))
 			continue
 		}
@@ -111,6 +112,8 @@ func (l *LdapAutoSynchronizer) syncRoutine(ldap *Ldap, stopChan chan struct{}) e
 		} else {
 			logs.Info(fmt.Sprintf("ldap autosync success, %d new users, %d existing users", len(users)-len(existed), len(existed)))
 		}
+
+		conn.Close()
 	}
 }
 
diff --git a/object/ldap_conn.go b/object/ldap_conn.go
index bc9f716d4efb..71d93d74163d 100644
--- a/object/ldap_conn.go
+++ b/object/ldap_conn.go
@@ -81,6 +81,17 @@ func (ldap *Ldap) GetLdapConn() (c *LdapConn, err error) {
 	return &LdapConn{Conn: conn, IsAD: isAD}, nil
 }
 
+func (l *LdapConn) Close() {
+	if l.Conn == nil {
+		return
+	}
+
+	err := l.Conn.Unbind()
+	if err != nil {
+		panic(err)
+	}
+}
+
 func isMicrosoftAD(Conn *goldap.Conn) (bool, error) {
 	SearchFilter := "(objectClass=*)"
 	SearchAttributes := []string{"vendorname", "vendorversion", "isGlobalCatalogReady", "forestFunctionality"}