An experimental pistachio sorting device based on impact acoustic of pistachio was designed in the study. Judged by the integrated logarithmic decrement difference, the impact acoustic characteristics of pistachio caused by different microphone position, different falling height of pistachios and different tilt angle of collision block was compared and analyzed. The research shows that the result could achieve better sorting reliability under two conditions. First, when the angle between the microphone and the impact surface is 45° with the distance between the microphone and the impact point is about 10 cm; Second, when the pistachios falling height is between 70 cm to 100 cm and the tilt angle of collision block is 30° with the microphone position unchanged, and the sorting accuracy rate of pistachio sorting equipment can be increased from 70% to 100%.