According to the nuclear safety regulations,verification and validation(V&V)activities should be carried out during the software development process.Based on the research of the regulations and standards and engineering experience,a suitable safety class DCS application software V&V system is established.This V&V system has been used in a nuclear power plant project,to ensure the quality of the software and the successful implementation of the project.The system also has good prospects in the follow-up projects,such as HRR1000 and AP1000 advanced reactors.