Abstract: In order to study the influences of deformation, stress and fatigue on the core components of high-speed mechanical switches during the opening process, mathematical modeling and multi-physical field coupling simulation analysis methods are adopted, and Workbench is used as the platform to analyze the opening process of the operating mechanism based on electromagnetic field, mechanical field, transient structural field, and fatigue life. Firstly, the opening model of high-speed mechanical switch is established by using modeling software. Secondly, the stress and deformation distribution of the core components are simulated by multiple physical fields. Finally, the effects of the high-speed mechanical switch on the fatigue life and mechanical stability of the repulsion disk, drive lever, and coupling under different materials, structures, and discharge current conditions are analyzed. The simulation results show that the repulsion disk made of aviation aluminum 7075-T6 and chamfered has less deformation; proper repulsion disc thickness and drive lever diameter can effectively reduce stress and deformation; The coupling with 40Cr has the longest fatigue life. Reducing the peak value of repulsion can effectively reduce the deformation stress and prolong the fatigue life, whereas, the effect of prolonging the action time of repulsion is not obvious. This paper provides a more comprehensive technical support for the problem that a single electromagnetic field cannot effectively reflect the deformation stress and fatigue of the core components in the opening process of high-speed mechanical switches.