diff --git a/sdk_tb_linkedmall/errors.go b/sdk_tb_linkedmall/errors.go
new file mode 100644
index 0000000..d3a69d1
--- /dev/null
+++ b/sdk_tb_linkedmall/errors.go
@@ -0,0 +1,58 @@
+package sdk_tb_linkedmall
+
+import "fmt"
+
+// APIError 表示API调用返回的业务错误
+type APIError struct {
+	Code       string // 错误码
+	Message    string // 错误信息
+	SubCode    string // 子错误码
+	SubMessage string // 子错误信息
+	RequestId  string // 请求ID
+}
+
+func (e *APIError) Error() string {
+	return fmt.Sprintf("linkedmall api error: code=%s, message=%s, subCode=%s, subMessage=%s, requestId=%s",
+		e.Code, e.Message, e.SubCode, e.SubMessage, e.RequestId)
+}
+
+// NewAPIError 创建API错误
+func NewAPIError(code, message, subCode, subMessage, requestId string) *APIError {
+	return &APIError{
+		Code:       code,
+		Message:    message,
+		SubCode:    subCode,
+		SubMessage: subMessage,
+		RequestId:  requestId,
+	}
+}
+
+// IsBusinessSuccess 判断业务是否成功（需要HTTP 200 + Success=true）
+func IsBusinessSuccess(resp *CommonResponse) bool {
+	return resp != nil && resp.Success
+}
+
+// CheckResponse 检查响应是否成功，失败返回error
+func CheckResponse(resp *CommonResponse) error {
+	if resp == nil {
+		return fmt.Errorf("linkedmall: response is nil")
+	}
+	if !resp.Success {
+		return NewAPIError(resp.Code, resp.Message, resp.SubCode, resp.SubMessage, resp.RequestId)
+	}
+	return nil
+}
+
+// 预定义错误码常量
+const (
+	ErrCodeShopTypeInvalid               = "ShopTypeInvalid"
+	ErrCodeSkuPriceNotUnique             = "SkuPriceUnique"
+	ErrCodePurchaseOrderNotFound         = "PurchaseOrderNotFound"
+	ErrCodeRefundNumberMustLessThanOrder = "RefundNumberMustLessThanOrder"
+	ErrCodeRefundAmountMustLessThanOrder = "RefundAmountMustLessThanOrder"
+	ErrCodeHasNoPrivilege                = "HasNoPrivilege"
+	ErrCodeOrderNotFound                 = "OrderNotFound"
+	ErrCodeShopNotFind                   = "ShopNotFind"
+	ErrCodeSavePurchaseOrderError        = "SavePurchaseOrderError"
+	ErrCodeOuterPurchaseOrderIdExist     = "OuterPurchaseOrderIdExist"
+)
\ No newline at end of file