The study focused on ensuring the safety of nuclear power plants by verifying and validating the software used in their digital control systems. Different types of software require different testing methods to ensure they work correctly. The research looked at the process of software verification and validation in Chinese nuclear power plants, particularly in the LingAo Phase II and CPR1000 projects. By analyzing third-party verification methods, the study identified key points and techniques to improve the safety and reliability of control systems in nuclear power plants.