Abstract: In view of the mutual restriction question of obvious rate and damage rate, orthogonal experiment was carried out to study the working performance of poke finger wheel type potato digger in this paper. Through range analysis and variance analysis on experiment test, the main factors influencing the obvious rate was got as follows: the poke finger wheel speed, longitudinal distance between shovel shaft and poke finger wheel axle, the length of digging shovel. The order of the factors that influencing the damage rate from big to small was as follows: the poke finger wheel speed, the length of digging shovel, longitudinal distance between shovel shaft and poke finger wheel axle. Considering the influence extent of tested factors on the potato obvious and damage rate and its duty in the task of potato digger, the parameters of the equipment were optimized as follows: the poke finger wheel speed was 142 r/min; the length of digging shovel was 480mm; longitudinal distance between shovel shaft and poke finger wheel axle was 420mm. Repeat testing showed that obvious rate was more than 96% and damage rate was less than 5%.