Abstract: The electromagnetic repulsion mechanism (EMRM) is an important device to realize the rapid breaking of circuit breakers. Due to the driving principle of eddy current repulsion, the efficiency of the mechanism is low. In this paper, an efficiency optimization method of electromagnetic repulsive force mechanism based on the analysis of frequency domain parameters is proposed. Firstly, the finite element simulation model of the mechanism is established, and the current and electromagnetic force are compared and analyzed when the repulsive disk is fixed and moves. It is found that the mutual inductance changes during the motion process have a negligible influence on the current and electromagnetic force, and the mutual inductance can be simplified to a constant in the analytical analysis. Then, the accuracy of equivalent parameters calculated by different methods for analytical analysis is compared. Moreover, f_ω frequency domain parameters can be used to analyze current better. The influence of frequency and coil structure on mutual inductance gradient is further analyzed. The conclusion that mutual inductance gradient can be simplified as linear reduction is put forward, and the analytical formula of electromagnetic force is obtained. Finally, the efficiency optimization method of the electromagnetic repulsion mechanism is proposed on the basis of the analytic calculation of the parameters in the frequency domain, and the parameters of the repulsion mechanism are optimized in this paper.