You cannot use the national flag pattern to be printed on the product, otherwise, it is illegal.

Article 7 of the "Advertising Law" stipulates: "Advertising content should be beneficial to people's physical and mental health, promote the improvement of the quality of goods and services, protect the legitimate rights and interests of consumers, abide by social ethics and professional ethics, maintain The dignity and interests of the country. Advertisements shall not have the following circumstances:

(1) Use the flag, national emblem, and national anthem of the People's Republic of China;..."

The National Flag Law also has relevant provisions.