Flight simulators are important equipment for simulating and reproducing real flight activities, and the simulation effects of simulators have been attracting wide attention. However, the motion platform based on the classical washout algorithm for restoring motion trajectories faces problems such as conservative parameter settings and poor simulation effects. Therefore, this study proposes a filter parameter optimization method based on an improved artificial fish swarm algorithm. Specifically, by the human vestibular perception error model, the corresponding objective function is obtained; then, the improved fish swarm algorithm is used to optimize the natural cut-off frequency in the filter; finally, the optimized filter parameters are simulated and verified through the simulation model built on Simulink. The results show that compared with those of the classical washout algorithm and the basic artificial fish swarm algorithm, the new parameters obtained by the improved algorithm can effectively improve the motion perception effect during the algorithm washout, reduce the motion error, and save more motion space.