Abstract: 【Objective】 It is important to study the main factors affecting the depth of overtopping on the surface of the plough body, so this project aims to establish a prediction model for overtopping, in order to improve the quality of ploughing and to provide a theoretical basis for the design of the surface of the plough body. 【Methods】 The orthogonal experimental design method was used to analyse the effects of structural parameters such as plough body push angle, trace lateral displacement, soil turning angle and soil turning curve on the distribution of top soil after ploughing and tilling based on discrete element simulation. A prediction model of top soil distribution after ploughing was established and validated using nonlinear regression analysis. 【Results】 The effect of the slope of the change in tangent inclination of the top of the tillage curve at the plough breast on the distribution of topsoil after ploughing was significant (P<0.05) in both cases, and the effect of the amount of trajectory lateral shift on the content of topsoil within the 100-200 mm soil layer above and below the surface was significant (P<0.05), and the effect of the slope of the change in tangent inclination of the top of the tillage curve at the plough breast on the content of topsoil within the subsoil layer below the surface was greater than the amount of trajectory lateral shift. 【Conclusion】 With the increase of the slope of the tangent inclination of the top of the tilling curve in the plough breast change, the topsoil content within the soil layer above the surface gradually increases; with the increase of the lateral shift of the trace, the topsoil content within the soil layer above the surface shows a tendency of decreasing first and then increasing. The prediction model of topsoil distribution after ploughing can predict the topsoil content in each soil layer after ploughing under different structural parameters of the plough body surface, and the average error between the predicted and simulated values is less than 6%.