The sequential turbocharging switch valve needs to withstand high temperature and high pressure during the working process, which results in the creep phenomenon of switch valve. Based on the high temperature creep test data of 310S stainless steel, the creep mathematical model parameters were obtained, and the Norton creep mathematical model of material was established. The ANSYS finite element simulation software was used to simulate and analyze the stress field and uniaxial creep strain law of the sequential turbocharging switch valve under 18 000 h working condition; Based on Cocks-Ashby multiaxial creep coefficients, the multiaxial creep strain distribution law of valve was obtained by simulation analysis. The simulation results show that the average creep rate of valve with a large creep is 8%. After introducing the multiaxial creep coefficient, the multiaxial creep strain for the key nodes of valve is less than 2% except for a few structural sudden changes.