[en] The nuclear power plant protection relay is the key device to ensure the safe and stable operation of the nuclear power plant. It involves the implementation of the safety function of the nuclear power plant. The quality of the hardware and the software of the nuclear power plant relay both need to comply with nuclear safety related regulations. The software is verified and validated to ensure the safety and reliability. This paper summarizes the V and V method and technical characteristics of nuclear power plant safety software based on the V and V forensic process of the protection relay safety software of nuclear power plant, and provides reference for the subsequent development and evidence collection for the software V and V of nuclear power plant localization device. (authors)