Abstract: This paper performs the reliability analysis of reactor pressure vessel（RPV） with ANSYS.The analysis method include direct Monte Carlo Simulation method,Latin Hypercube Sampling,central composite design and Box-Behnken Matrix design.The RPV integrity reliability under given input condition is proposed.The result shows that the effects on the RPV base material reliability are internal press,allowable basic stress and elasticity modulus of base material in descending order,and the effects on the bolt reliability are allowable basic stress of bolt material,preload of bolt and internal press in descending order.