The parameter adjustment of the wash algorithm greatly affects its performance. Aiming at the deficiency of parameter adjustment of the current classical wash algorithm when it is applied to flight simulator, an improved wash algorithm based on MOEA/D multi-objective optimization is proposed. In order to minimize the human perception error between real and simulated motion, and to develop the platform under the condition of motion space limitation, several evaluation indexes of the washing algorithm were considered in the optimization process, and the parameters of the washing algorithm were optimized synchronously. To verify its effectiveness,the motion test platform of flight simulator was established and the improved algorithm was applied to optimize calculation. The washing algorithm before and after optimization is simulated and tested, results show that the optimized algorithm has great improvement in the homing response, phase delay and perceived amplitude, and has better stability. At the same time, optimizing the platform workspace and increasing the dynamic fidelity.