According to Article 2 of the Interrogation Standard for People's Police of Public Security Organs, interrogation is an interrogation and inspection act taken by the people's police according to law to safeguard public safety, prevent, detect and control illegal and criminal activities. The interrogation was conducted on the spot, and the freedom of the interrogated person was partially restricted. If it is forced to bind to the police station and other places, it does not belong to the inventory.

Investigation can be aimed at both administrative violations and criminal offences, and it is a mixed form of power. Interrogation is called "duty inquiry" in Japan, "stop search" in the United States and "stop search" in Britain. China's "People's Police Law" and "People's Police Interrogation Standard of Public Security Organs" all have provisions on police on-site interrogation procedures.

Interrogation is a double-edged sword. Interrogation procedure can play an important role in finding criminal suspects and arresting fugitives. 20 16 to may 1, the railway police checked their identity cards through interrogation procedures and arrested fugitives 1. 1 10,000 people. However, interrogation may also lead to suspicion, infringe on the legitimate rights and interests of the other party, such as selective interrogation by the police, discriminate against certain groups of people (such as migrant workers), or hurt the feelings of normal people. The key to the problem is to first make clear the legal requirements of interrogation procedures.