In order to improve the oil film lubrication characteristics of the spherical valve-plate pair with conical cylinder block, a multi-arc groove spherical valve-plate pair structure was proposed, and the genetic algorithm was used to optimize the multi-objective structure of the multi-arc groove spherical valve-plate pair. Firstly, the multi-arc groove valve-plate pair was theoretically modeled, the finite volume method was used to discretize the oil film pressure control equation and the circular tridiagonal matrix algorithm(CTDMA) was used to solve the pressure distribution of the spherical valve-plate pair. Secondly, the load-bearing characteristics of the multi-arc groove spherical valve-plate pair were simulated, the oil film thickness distribution and oil film pressure distribution of the spherical valve-plate pair with different arc groove structures were analyzed. Thirdly, the cylinder overturning angle, leakage loss and friction torque were used as the optimization objectives, the multi-objective genetic algorithm was used to optimize the structural parameters of the multiarc groove spherical valve-plate pair. The results showed that the multi-arc groove structure can improve the load-bearing capacity of the oil film of the spherical valve-plate pair, the minimum oil film thickness decrease for the arc groove structure ranged from 3.1% to 4.0%, and the maximum pressure increase significantly for the arc groove structure was 16.3%;while effectively reducing the leakage loss and friction torque. After optimization, the overall target performance was improved by 10.5%, cylinder overturning angle, leakage loss and friction torque were reduced by 5.1%, 8.1% and 5.9%, respectively, which effectively improved the lubrication performance of the spherical valve-plate pair.