Using ANSYS to calculate the force response curves with time history of pressure relief valve and dynamic characteristics; Solid structure was simplified to two single degree of freedom mass spring damper dynamic models which could be calculated by Newmark algorithm. The three-dimensional unsteady integral forms of ALE equation were solved by finite volume scheme based on spring analogy method and dynamic grid. A new discrete geometric conservation law and high-precision fluid and solid coupling algorithm were used to calculate the governing equations; the virtual mesh ventilation method was adopted to resolve the problem when multi bodies moved from contact to separation and the mesh topology changed. The results show that the outlet pressure of valve oscillated within wide range upstream pressurization rate, the average pressure is close to the theoretical value of static performance design. Through the flow field analysis, it can determine the main mechanism of two kinds of open fault and modify the model parameters to exclude anomalies.