Objective:In view of the existing rubber seed shelling machine, which have poor shelling and whole-kernel rate, is not enough to meet the needs of rubber seed shelling under different condition, a combined rubber seed shelling machine was designed. Through the combination of cutting and shearing of rubber seeds between the groove plate and the rotary blade, as well as extrusion and collision of the rotary blade roller, the shell is removed.Methods:The discrete element software EDEM was used to establish the discrete element model of rubber seed and shelling machine, and to simulate the separation process. Response surface method (RSM) was used to analyze the influence of shear extrusion clearance, blade roller speed and blade-roller installation phase on rubber seed shelling and whole-kernel rate. The best working parameters were optimized and verified by experiment.Results:The designed combined rubber seed sheller can achieve better shell kernel separation and obtain a higher kernel rate. When the shear extrusion clearance was 12.6 mm, the blade-roller speed was 300 r/min, and the blade-roller installation phase was 40.5°, the shelling rate and whole-kernel rate of rubber seed were 94.09% and 96.47%. According to the best parameter combination, the shelling rate and whole-kernel rate of rubber seed were 89.67% and 91.33%.Conclusion:In the design process of rubber seed shelling, the discrete element method can be effectively used to analyze the influence of different structural parameters on the performance indicators.