Abstract: Aiming at the problems of periodical tests for high safety significant systems in CPR1000 nuclear power unit, the optimization method for periodical tests for CPR1000 is proposed based on the methodology of periodical test design and safety analysis. For the periodical test of the classic instrument alarming, i.e., the residual heat removal system is not isolated and the reactor coolant system is with high pressure, the problems were analyzed and the optimization scheme is proposed. According to the optimization method for periodical tests presented, the safety of the optimization scheme is analyzed, which shows that the scheme is correct and valid. The optimization method for the periodical test of CPR1000 Nuclear Power Unit is beneficial to the nuclear safety.