In order to optimize the structure and movement parameters of the key parts of horizontal walnut peeling machine, a kind of horizontal green walnut peeling machine was designed in this paper. By analyzing the structure and working principle of the whole machine and its key parts, the peeling test was carried out by selecting different brush types, blade types and blade arrangement. The key parts of horizontal green walnut peeling machine were determined: C type brush, F type blade and h type blade arrangement. Through the peeling test of spindle speed and feeding amount, the operating parameters of horizontal green walnut peeling machine were determined: spindle speed 25~35 r/min, feeding amount 1 000~3 000 kg/h. Results: the cleaning rate was 92.12%, the damaged fruit rate was 4.28% of Xinxin 2 green walnut, the cleaning rate was 90.32%, the damaged fruit rate was 6.17% of Wen 185 green walnut, and the cleaning rate was 94.69%, the damaged fruit rate was 4.77% of Zha 343 green walnut under the conditions of the feeding amount of 2 000 kg/h, the spindle speed of 30 r/min, the peeling gap of 35 mm and the peeling angle of 2°.