Aimed the problem that the knifeedge seal used in the largescale structures with high vacuum operating condition can not meet the requirement of leakage rate during field setting,the feasibility of using Wheeler seal was studied.The proper preload of screw of knifeedge seal and Wheeler seal was determined by test method,and the repeated sealing performance of two common sealing methods was compared.The stress and strain of contact surface were analyzed by finite element method.The results indicate that compared with knifeedge seal,Wheeler seal can achieve effective sealing in a larger screw preload range.The knifeedge and Wheeler seal can both achieve effective sealing in the first time.However,when there is a structural defect occurred inthe secondary seal,the knifeedge seal must repair cutting edge or replace cooper seal ring to ensure effective sealing,while the Wheeler seal only needs to increase the screw moment to ensure effective sealing,so Wheeler seal is more reliable