Legal analysis: Whether it is illegal to print the national flag on clothes depends on the situation. It is not illegal to print the national flag on clothes and use it correctly. In the relevant laws, it is not forbidden whether the cloth with the national flag pattern can be made into clothes, but according to the law, it can be made without prohibition, so clothes made with the national flag do not violate the law. In the process of making clothes, it is not illegal to insult the national flag in public places if it is not intentionally burned, damaged, scribbled, defiled or trampled. However, if it is produced on a large scale, and it is suspected of trademark and advertising problems and acts that undermine the dignity of the national flag, it is illegal.

Legal basis: People's Republic of China (PRC) National Flag Law.

Article 19 No damaged, defaced, faded or substandard national flag shall be hoisted or used, and no national flag shall be hoisted or used upside down, inserted upside down or in other ways that are detrimental to the dignity of the national flag. Don't throw away the national flag at will. Damaged, defaced, faded or substandard national flags shall be recovered and disposed of in accordance with relevant state regulations. After the large-scale mass activities, the organizers of the activities shall take back or properly dispose of the national flag used at the event site.

Article 20 The national flag and its patterns shall not be used as trademarks, patterns granted patent rights or commercial advertisements, and shall not be used in inappropriate occasions such as private funeral activities.