If the illegal immigration is caught, the police will detain the perpetrator for not more than five days or impose a fine of not more than 500 yuan. However, if the circumstances of illegal immigration are serious, it will be deemed to constitute the crime of illegally crossing the border, and the perpetrator will be sentenced to fixed-term imprisonment of not more than one year, criminal detention or public surveillance, and will also be fined; If the perpetrator illegally crosses the national border (frontier) by participating in terrorist organizations, receiving terrorist training or carrying out terrorist activities, he shall be sentenced to fixed-term imprisonment of not less than one year but not more than three years and shall also be fined.
 The so-called serious circumstances of illegally crossing the border of a country refer to the following circumstances: (1) conduct outside the country that damages the national interests;
 （2） Having crossed the national (frontier) border three or more times or three or more people have crossed the national (frontier) border in a group;
 （3） Soliciting or luring others to illegally cross the national border (frontier);
 （4） Colluding with overseas organizations and personnel to illegally cross the national border (frontier);
 （5） Those who illegally cross the national (frontier) border again within one year after being punished for illegally crossing the national (frontier) border;
 （6） Other serious circumstances.
 [Legal Basis]
 Article 62 of the Law of the People's Republic of China on Administrative Penalties for Public Security stipulates that those who illegally cross the national border (frontier) shall be detained for not more than five days or fined not more than 500 yuan.