In order to solve the problem that the ammunition sloshing affects the reliability of interface handover of ammunition feeding system, a design method of reducing ammunition offset amplitude is proposed. According to the condition of feeding rate and structural parameters of ammunition feeding system, based on the basic assumption of structural parameters of ammunition feeding system, a simplified model of leaf spring structure is established. The motion law of ammunition unit is described by using motion equation, using Matlab for loop iterative calculation, and the optimal value of motion parameters is solved by taking the ammunition offset amplitude as the objective function and carried out on certain type naval gun ammunition feeding system verification. The experimental results show the effectiveness of the method.