Analysis of structure strength in mid-voltage DC high-speed operating mechanism has been the difficult problem for design and optimization. This paper develops the global flexible body model for the analysis of structure strength in mid-voltage DC high-speed switch based on the flexible body theory and transient dynamic methods. Compared with the commonly used simulation model

the novel model proposed the method of applying distributed load on repulsion plate and took the Lorentz force and inertia force into consideration

during the motor process

lead to a more accurate solution of the stress distribution of moving components. This paper analyzed the structure strength of moving components during opening process to acquire the dynamic stress and strain distribution. The validity of the model has been verified by comparing with experimental results. This paper provides important basis to the optimization of structure strength in high-speed operating mechanism.