Cybercrime refers to a new form of crime generated with the application and prevalence of computer technology. In China, there are increasingly more instances of unauthorized access to computer systems every year, which has severely affected network security and the property security of the people, and even national security. This paper delves deeper and more methodically into the problems surrounding the criminal act of unlawful access to computer information systems. The ambiguous definition and limited reach of the criminal object make Chinas punishment for unauthorised access to computer systems less effective., the crossover of the criminal law system caused by the contradiction of legislative logic, as well as the insufficient prevention of too lenient penalties. Based on the above legislative deficiencies, it is imperative to improve the criminal law system, expand the protection scope of the first clause of Article 285 of the Criminal Law, Increase the number of cases that are investigated and prosecuted, explain computer information systems in the context of state affairs, expand the definition of state affairs computer information systems, and strictly regulate the amount of crime that is legal. Additionally, it is essential to establish an independent status for data crimes by adding provisions on data security protection concerning the three major computer information systems; increasing the intensity of punishment, raising the range of statutory penalties, and adding property penalties, thereby imposing a comprehensive regulation on illegal intrusion into computer information systems.