Abstract: Abstract: The crop rotation of rice and rapeseed is the main planting pattern for winter rapeseed in South China. In a traditional broad-ridge shallow-furrow planting mode, the ditching machine plow or rotary disc is used to ditch the field. However, the plow cannot solve the problem of high rice stubble in field, while the rotary disc is easy to be entangled by grass and backwater mud in high humidity field, which often causes the traditional parts of ditching and ridging for rapeseed to be loose and collapse. Aimed to solve the problem of high stubble of rice after harvesting and reduce the influence of high-water content in sticky soil, in this paper, a plow-rotary style ditching and ridging device for rapeseed seeding is designed, which can meet the requirements of narrow ridge and deep ditch. Based on the maximum transported soil volume and the triangular wedge model, the structural parameters such as the embedded angle, the angle of the wing and the length of the wing are designed. The installing way of the rotary machetes and the straight tilling blade are innovated in the same roller. The turning radius and the length of each functional blade are optimized based on the biggest installation space, the uniformity coefficient of groove surface, the stability of ridge high and the soil return rate are taken as evaluating indicator. The turning radius of straight cutting blade, and the length and angle of wing are taken as experiment factors, and the multifactor quadratic orthogonal rotation combination test was carried out. The quadratic model is selected to establish the regression model which is related to the uniformity coefficient of groove surface, the stability of ridge high and the soil return rate. The F test and variance analysis are carried out for the coefficients of the regression model to establish quadratic multiple regression model related to the evaluation indices and influence factors. The results show that, the order of the factors influencing the uniformity coefficient of groove surface and the stability of ridge high from high to low is the turning radius of straight cutting blade, the length of wing and the angle of wing; the order of the factors influencing the soil return rate from high to low is the length of wing, the angle of wing and the rotary radius of straight cutting blade. The optimal combination of operating parameters is obtained after the application of the optimization function of the software: The turning radius of straight cutting blade is 351 mm, the length of wing is 78 cm and the angle of wing is 41°. And the evaluation indices are analyzed and the optimum values are selected: The uniformity coefficient of groove surface and the stability of ridge high reach the maximum values, and the soil return rate gets the minimum value. The optimal combination of operating parameters is verified, which meets the design requirements. All of the evaluation indices are basically the same as the software analysis, and the relative errors are less than 1%. The study results may provide technical support for high yield cultivation of rapeseed ridge planting.