Abstract: With the increasing of neutron irradiation time, the sensitivity of the vanadium detectors will reduce and even lose efficacy. Therefore, the vanadium detectors need to be integral replaced after operating a certain period of time. This paper mainly discusses and analyzes the design and implementation of the physics tests to verify the performance of the vanadium detectors of the CANDU6 reactor after replacement for the first time. The results meet the requirements through the analysis and verification, lying an important foundation for the safe and stable operation of the plant in the future and providing an important reference for the similar work in the future.