Research on drag reduction of farm machinery riding on paddy field has important energy conservation significance.This paper established the discrete element model of paddy soil with EDEM and the interaction between the surface of machine parts and Saturated soil layer,designed the surface of machine parts which contact with soil by the bionic design method,presented a simulation of the soil particles migration when soil particles contact with the bionic surface and smooth surface respectively.The particle trajectory and the force situation of the sample piece were obtained.The results showed that the bionic sample piece can reduce the drag.This paper analyzed the mechanism of drag reduction of the bionic surface of machine parts that contact with soil by the tribology theory.Finally,the drug of the two different sample piece was measured by self-made soil bin experimental rig and a force sensor.The results showed that the bionic sample piece can reduce the drag by up to 16.7%.This paper provided a reference for the research on mechanism of drag reduction of farm machinery riding on paddy field.