Unlike other things, formal military uniforms can only be worn by soldiers. Soldiers are responsible for defending their country, so their image is very important. If someone wears a military uniform and does bad things outside after leaving the army, it will damage the image of the army. Ordinary soldiers can take quilts, washbasins and so on when they leave the army. But formal military uniforms can't, and hats, badges and epaulettes can't be taken out.

According to the Regulations on the Administration of Military Uniforms

Article 9 Soldiers and those who can wear military uniforms in accordance with laws, regulations and relevant military regulations shall wear military uniforms in accordance with relevant regulations. Military security personnel on duty should strengthen inspections and pickets, and promptly correct violations of wearing military uniforms. Artists in film and television production and cultural performance units who need to wear military uniforms to play the role of soldiers shall abide by the military regulations on wearing military uniforms and shall not damage the image of the army and soldiers. You are not allowed to wear military uniforms when shooting or performing.

1988, Article 6 of the Regulations of China People's Liberation Army Officers' Ranks stipulates that officers in active service who are transferred to the reserve shall be labeled as "reserve". If an officer in active service retires, his rank shall be retained, and the rank shall be preceded by "Retired". However, there are no corresponding laws, regulations and normative documents on how to wear military uniforms and whether to wear military ranks.

Extended data:

It is a common practice for retired soldiers to wear military uniforms in most countries in the world. Many countries clearly stipulate that retired soldiers can wear their uniforms at that time or at the time of final service on formal occasions or important festivals, and they can wear various medals, commemorative medals or ribbons obtained during their service on their uniforms.

American soldiers still have military status after retirement, and they can wear military uniforms and ranks when participating in important activities. After retirement, Russian soldiers retained their original ranks. Retired soldiers who have served in length of military service for 25 years and made special contributions can wear military uniforms and ranks at major festivals and important activities, and can also be invited to participate in military exercises, military art and military parade activities in the region.

Retired soldiers of the Japanese Self-Defense Force maintain their ranks for life and enjoy courtesy. Famous generals from Yugoslavia, Hungary, Poland and other countries can be invited to attend their national day and army day receptions after retirement, and retired generals who participated in World War II can also be invited to attend the national day and army day receptions of Eastern European allies. They can all wear military uniforms. When the Australian and Canadian governments hold major commemorative and celebration activities, they specially reserve seats and invite retired military representatives to wear medals to attend.

References:

People's Network-Can retired soldiers wear military uniforms?