A semi-feeding peanut picking test-bed was developed to carry out the studies on optimized design and experiment on the structural and motion parameters of semi-feeding peanut picking device. Based on the motion analysis of picking process, ideal position state and parameter relationship of pods cluster during the picking section were determined to ensure that all the pods cluster could pass through the best picking areas by bottom-up and gradual-orderly mode. Influencing factors of picking frequency and strength as well as the influence on the picking performance were analyzed. On the basis of picking mechanism analysis and the experimental verification, the picking roller employed six backward-curved blades. After the multi-criteria response surface experiments, the optimized combination of structural and operational parameters were obtained as follows: the roller length was 1.200mm, the included angle between chain and roller was 7.2°, the roller diameter was 152.5mm, roller overlap distance was 5mm, roller rotate speed was 371r/min, chain conveying speed was 1.025m/s.