diff --git a/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type.go b/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type.go
index fbc540e..305691e 100644
--- a/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type.go
+++ b/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type.go
@@ -4,16 +4,7 @@ import "strings"
 
 const defaultPlateType = "02"
 
-// plateTypeToPlateColor 将车牌类型编码转换为 ETC 人车关系核验所需的车牌颜色。
-func plateTypeToPlateColor(plateType string) string {
-	code := normalizePlateType(plateType)
-	if color, ok := plateTypePlateColorMap[code]; ok {
-		return color
-	}
-	return "0"
-}
-
-// normalizePlateType 归一化车牌类型，空值默认小型汽车（02）。
+// normalizePlateType 归一化车牌类型，空值默认小型汽车（02），供行驶证 V2 使用。
 func normalizePlateType(plateType string) string {
 	code := strings.TrimSpace(plateType)
 	if code == "" {
@@ -22,11 +13,25 @@ func normalizePlateType(plateType string) string {
 	return code
 }
 
+// etcPlateColorParam 将车牌类型转为 ETC 接口的 plateColor。
+// 第二个返回值表示是否需要传 plateColor；不传时由数据宝按默认蓝牌处理。
+func etcPlateColorParam(plateType string) (color string, include bool) {
+	code := strings.TrimSpace(plateType)
+	if code == "" || code == "02" {
+		return "", false
+	}
+	color, ok := plateTypePlateColorMap[code]
+	if !ok || color == "0" {
+		return "", false
+	}
+	return color, true
+}
+
 // plateTypePlateColorMap 车牌类型 -> ETC 车牌颜色
 // 0蓝 1黄 2黑 3白 4渐变绿 5黄绿双拼 6蓝白渐变 7临时 11绿 12红
 var plateTypePlateColorMap = map[string]string{
 	"01": "1",  // 大型汽车 -> 黄色
-	"02": "0",  // 小型汽车 -> 蓝色
+	"02": "0",  // 小型汽车 -> 蓝色（默认不传 plateColor）
 	"03": "2",  // 使馆汽车 -> 黑色
 	"04": "2",  // 领馆汽车 -> 黑色
 	"05": "2",  // 境外汽车 -> 黑色
@@ -47,7 +52,30 @@ var plateTypePlateColorMap = map[string]string{
 	"22": "7",  // 临时行驶车 -> 临时牌照
 	"23": "3",  // 警用汽车 -> 白色
 	"24": "3",  // 警用摩托 -> 白色
-	"38": "0",  // 预留 -> 蓝色
+	"38": "0",  // 预留 -> 蓝色（等同默认，不传）
 	"51": "5",  // 新能源大型车 -> 黄绿双拼色
 	"52": "11", // 新能源小型车 -> 绿色
 }
+
+func buildETCShujubaoParams(plateNo, name, plateType string) map[string]interface{} {
+	params := map[string]interface{}{
+		"key":   "a2f32fc54b44ebc85b97a2aaff1734ec",
+		"carNo": plateNo,
+		"name":  name,
+	}
+	if color, include := etcPlateColorParam(plateType); include {
+		params["plateColor"] = color
+	}
+	return params
+}
+
+func buildETCTianyuanParams(plateNo, name, plateType string) map[string]string {
+	params := map[string]string{
+		"plate_no": plateNo,
+		"name":     name,
+	}
+	if color, include := etcPlateColorParam(plateType); include {
+		params["plate_color"] = color
+	}
+	return params
+}
diff --git a/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type_test.go b/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type_test.go
index d4a6485..a152992 100644
--- a/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type_test.go
+++ b/internal/domains/api/services/processors/qcxg/qcxg7k2n_plate_type_test.go
@@ -2,24 +2,27 @@ package qcxg
 
 import "testing"
 
-func TestPlateTypeToPlateColor(t *testing.T) {
+func TestEtcPlateColorParam(t *testing.T) {
 	tests := []struct {
-		plateType string
-		want      string
+		plateType     string
+		wantColor     string
+		wantInclude   bool
 	}{
-		{"", "0"},
-		{"02", "0"},
-		{"01", "1"},
-		{"52", "11"},
-		{"51", "5"},
-		{"23", "3"},
-		{"22", "7"},
-		{"99", "0"},
+		{"", "", false},
+		{"02", "", false},
+		{"01", "1", true},
+		{"52", "11", true},
+		{"51", "5", true},
+		{"23", "3", true},
+		{"38", "", false},
+		{"99", "", false},
 	}
 
 	for _, tt := range tests {
-		if got := plateTypeToPlateColor(tt.plateType); got != tt.want {
-			t.Fatalf("plateTypeToPlateColor(%q) = %q, want %q", tt.plateType, got, tt.want)
+		color, include := etcPlateColorParam(tt.plateType)
+		if color != tt.wantColor || include != tt.wantInclude {
+			t.Fatalf("etcPlateColorParam(%q) = (%q, %v), want (%q, %v)",
+				tt.plateType, color, include, tt.wantColor, tt.wantInclude)
 		}
 	}
 }
@@ -32,3 +35,15 @@ func TestNormalizePlateType(t *testing.T) {
 		t.Fatalf("normalizePlateType trim = %q, want 51", got)
 	}
 }
+
+func TestBuildETCShujubaoParams(t *testing.T) {
+	params := buildETCShujubaoParams("桂A12345", "张三", "01")
+	if params["plateColor"] != "1" {
+		t.Fatalf("plateColor = %v, want 1", params["plateColor"])
+	}
+
+	params = buildETCShujubaoParams("桂A12345", "张三", "")
+	if _, ok := params["plateColor"]; ok {
+		t.Fatalf("default should not include plateColor, got %v", params)
+	}
+}
diff --git a/internal/domains/api/services/processors/qcxg/qcxg7k2n_processor.go b/internal/domains/api/services/processors/qcxg/qcxg7k2n_processor.go
index 83c7697..fbda332 100644
--- a/internal/domains/api/services/processors/qcxg/qcxg7k2n_processor.go
+++ b/internal/domains/api/services/processors/qcxg/qcxg7k2n_processor.go
@@ -23,12 +23,7 @@ func ProcessQCXG7K2NRequest(ctx context.Context, params []byte, deps *processors
 	}
 
 	plateType := normalizePlateType(paramsDto.PlateType)
-	etcParams := map[string]interface{}{
-		"key":        "a2f32fc54b44ebc85b97a2aaff1734ec",
-		"carNo":      paramsDto.PlateNo,
-		"name":       paramsDto.Name,
-		"plateColor": plateTypeToPlateColor(paramsDto.PlateType),
-	}
+	etcParams := buildETCShujubaoParams(paramsDto.PlateNo, paramsDto.Name, paramsDto.PlateType)
 
 	data, err := deps.ShujubaoService.CallAPI(ctx, "/communication/personal/10093", etcParams)
 	if err == nil {