In order to solve the problems of high labor intensity, low efficiency, and high cost of manual picking after segmented harvesting of potatoes, a self-propelled potato picking device was designed. The picking device with a double layer reverse chain clamping and conveying function was designed to address the issue of soil accumulation in the feeding part of the picking device, which caused poor potato conveying and affected the overall operation efficiency. To determine the optimal operating parameters of the picking device, a Box-Benhnken test method was used based on the coupling simulation of discrete element software EDEM and multi body dynamics software RecurDyn. The potato flow rate and potato damage rate were used as experimental indicators, and the forward speed of the picking device, the depth of the picking shovel into the soil, the conveying chain speed of the picking device, and the reverse clamping chain speed were used as experimental factors. A four factor and three level experimental was conducted on the working parameters of the device, Design-Expert software was used to establish a quadratic polynomial regression model. After optimizing the regression model, a response surface curve was drawn to determine the optimal operating parameters of the device. Field experiments showed that when the forward speed of the picking device was 0.70m/s, the depth of the picking shovel into the soil was 120mm, the conveying chain speed of the picking device was 1.20m/s, and the reverse chain speed was 1.20m/s, the potato flow rate was 5.94kg/s, and the potato damage rate was 2.10%. Compared with the simulated theoretical values, the errors were 3.30% and 4.48%, respectively. The research result can provide reference for the design of potato picking devices.