In order to research the change rules of rubber fruit shelling efficiency with the related parameters and determine the optimum conditions of shelling efficiency, a rubber fruit shelling test machine was developed according to the principle of extrusion-grind. By using the single factor and orthogonal tests to analyze the influence rules of shelling rate with different extrusion pressures, friction velocity and material, and the optimal operating parameters of the machine was found. The results were as follows. With the increase of friction velocity, shelling rate firstly increased and then decreased, and it increased linearly with the increase of extrusion pressure. Moreover, it was also found that the shelling rate gradually reduced, when friction material were steel, plastic, wood, rubber. The influence factors of rubber fruit shelling rate from high to low in order were extrusion pressure, friction material, friction velocity. When it worded with extrusion pressure at 700 N, friction speed at 46 mm/s, with steel friction material, the shelling rate reached 81.8%. The results could provide test bases for the whole design of rubber fruit sheller.