High-voltage circuit breakers are key devices in high-voltage power systems, controlling both the on-off of specific lines and the reliable disconnecting of fault areas in the event of a fault to ensure the safe operation of other areas. The mechanical movement of the repulsive device and the force analysis are particularly important in the key structural model of the high-speed opening and breaking of the circuit breaker. In the process of high-speed stamping and resetting mechanism, the key components in the valve body, such as the spool, are subjected to the pressure of the hydraulic fluid with constantly changing pressure. The value of the pressure will not always be constant. The impact force on the mechanism is fast and instantaneous, while the fluid force is continuous, so the analysis of the fluid force becomes critical in the inertia phase and buffer phase of the repulsive mechanism movement. To address this issue, in order to obtain simulation data results closer to the real working conditions, we conduct a study of fluid-structure interaction simulation for structures in repulsive devices.