根据湿式多片离合器与制动器的工作特性，综合机械和热力学因素，提出了无因次结构参数的评价指标；利用数值方法求得理论最优解，揭示了无因次结构参数影响离合器与制动器工作性能的内在规律。数值解与试验统计结果相吻合，表明理论分析正确、有效。 According to the working characteristics of wet multi-plate clutches and brakes and the comprehensive mechanical and thermodynamic factors, the evaluation indexes of dimensionless structure parameters are put forward. The theoretical optimal solution is obtained by numerical method, and the influence of dimensionless structure parameters on the work of clutches and brakes The inherent law of performance. The numerical solution is consistent with the experimental statistical results, indicating that the theoretical analysis is correct and effective.