Abstract: As the subject whose rights are infringed in criminal cases, the victim's civil rights are guaranteed through criminal incidental civil action or a separate civil action. Based on the requirement of maintaining the unity of the rule of law, China adopts the system of collateral civil action to protect the civil rights of victims. However, it is difficult to play a positive role in judicial practice, which deviates from the original intention of designing the system of criminal incidental civil action. Therefore, this article theoretically demonstrates the legitimacy of perpetrators' civil liability in criminal cases, clarifies the scope of accepting cases, the civil compensation standard and its impact on the penalty in criminal incidental civil action, and discusses the organic unity of state penalty power, the victims' civil right protection and the perpetrators' right protection, so as to improve the system of criminal incidental civil action in China.