diff --git a/errors/gerror/gerror_error.go b/errors/gerror/gerror_error.go
index 64b72fc76..d58b83ab2 100644
--- a/errors/gerror/gerror_error.go
+++ b/errors/gerror/gerror_error.go
@@ -9,6 +9,7 @@ package gerror
 import (
 	"bytes"
 	"fmt"
+	"github.com/gogf/gf/internal/intlog"
 	"io"
 	"runtime"
 	"strings"
@@ -22,7 +23,7 @@ type Error struct {
 }
 
 const (
-	gFILTER_KEY = "github.com/gogf/gf/"
+	gFILTER_KEY = "/errors/gerror/gerror"
 )
 
 var (
@@ -130,6 +131,19 @@ func formatSubStack(st stack, buffer *bytes.Buffer) {
 			if strings.Contains(file, gFILTER_KEY) {
 				continue
 			}
+			if !intlog.IsInGFDevelop() {
+				// Avoid GF stacks if not in GF development.
+				if strings.Contains(file, "github.com/gogf/gf/") {
+					continue
+				}
+				if strings.Contains(file, "github.com/gogf/gf@") {
+					continue
+				}
+			}
+			// Avoid stack string like "<autogenerated>"
+			if strings.Contains(file, "<") {
+				continue
+			}
 			if goRootForFilter != "" && len(file) >= len(goRootForFilter) && file[0:len(goRootForFilter)] == goRootForFilter {
 				continue
 			}
diff --git a/internal/empty/empty.go b/internal/empty/empty.go
index 6c9a632d8..6268fa4eb 100644
--- a/internal/empty/empty.go
+++ b/internal/empty/empty.go
@@ -70,3 +70,24 @@ func IsEmpty(value interface{}) bool {
 	}
 	return false
 }
+
+// IsNil checks whether given <value> is nil.
+// Note that it's using reflect feature which affects performance a little bit.
+func IsNil(value interface{}) bool {
+	if value == nil {
+		return true
+	}
+	rv := reflect.ValueOf(value)
+	switch rv.Kind() {
+	case reflect.Chan,
+		reflect.Map,
+		reflect.Slice,
+		reflect.Array,
+		reflect.Func,
+		reflect.Ptr,
+		reflect.Interface,
+		reflect.UnsafePointer:
+		return rv.IsNil()
+	}
+	return false
+}
diff --git a/internal/intlog/intlog.go b/internal/intlog/intlog.go
index 4ad11d629..c0fa61042 100644
--- a/internal/intlog/intlog.go
+++ b/internal/intlog/intlog.go
@@ -31,6 +31,11 @@ func init() {
 	}
 }
 
+// IsInGFDevelop checks and returns whether current process is in GF development.
+func IsInGFDevelop() bool {
+	return isInGFDevelop
+}
+
 // Print prints <v> with newline using fmt.Println.
 // The parameter <v> can be multiple variables.
 func Print(v ...interface{}) {
diff --git a/net/ghttp/ghttp_unit_param_struct_test.go b/net/ghttp/ghttp_unit_param_struct_test.go
index bf140ef9a..7f531145f 100644
--- a/net/ghttp/ghttp_unit_param_struct_test.go
+++ b/net/ghttp/ghttp_unit_param_struct_test.go
@@ -22,6 +22,7 @@ func Test_Params_Struct(t *testing.T) {
 	type User struct {
 		Id    int
 		Name  string
+		Time  *time.Time
 		Pass1 string `params:"password1"`
 		Pass2 string `params:"password2" gvalid:"passwd1 @required|length:2,20|password3#||密码强度不足"`
 	}
diff --git a/util/gconv/gconv.go b/util/gconv/gconv.go
index 84ebe7968..d33010369 100644
--- a/util/gconv/gconv.go
+++ b/util/gconv/gconv.go
@@ -10,9 +10,12 @@ package gconv
 import (
 	"encoding/json"
 	"fmt"
+	"github.com/gogf/gf/internal/empty"
+	"github.com/gogf/gf/os/gtime"
 	"reflect"
 	"strconv"
 	"strings"
+	"time"
 
 	"github.com/gogf/gf/encoding/gbinary"
 )
@@ -149,6 +152,7 @@ func Runes(i interface{}) []rune {
 }
 
 // String converts <i> to string.
+// It's most common used converting function.
 func String(i interface{}) string {
 	if i == nil {
 		return ""
@@ -186,7 +190,20 @@ func String(i interface{}) string {
 		return string(value)
 	case []rune:
 		return string(value)
+	case *time.Time:
+		if value == nil {
+			return ""
+		}
+		return value.String()
+	case *gtime.Time:
+		if value == nil {
+			return ""
+		}
+		return value.String()
 	default:
+		if empty.IsNil(value) {
+			return ""
+		}
 		if f, ok := value.(apiString); ok {
 			// If the variable implements the String() interface,
 			// then use that interface to perform the conversion