Abstract:In the Northeastern China, due to unclear change principles of force and energy consumption during maize straw chopping process, the lower maize straw chopping quality is acquired which is not conducive to the decomposition of chopped straw because of the cold weather. This limits the application and promotion of maize straw retention technology. However, the area of the cropland with obstruction factors, such as poor soil, soil acidification is about 13 million hectares, which seriously affects the food security in China. Therefore, in order to solve above problems, the dynamic supporting type maize straw chopping retention device with different rotation speeds of disc blade was designed, The maize straw chopping retention device mainly included the collecting and chopping device, which was used to collect and transfer the maize straw in the filed surface, and the logarithmic spiral supporting disc device, which was used for dynamic support for the chopping of the maize straw combined with collecting and chopping device. In addition, the logarithmic spiral supporting disc blade was designed based on the slidecutting principle and the angle, thickness and length of the cutting edge and bent angle for the collecting and chopping blade were 20°, 3 mm, 45 mm and 40°, respectively. The rotation radius of the collecting and chopping blade and the logarithmic spiral supporting disc blade all were 250 mm. According to the force status of maize stalk in the chopping process, the chopping process was divided into three stages: collecting stage, transformation stage and chopping stage. In each stage, the force equation of maize straw was established, and it was found that the angular velocity of collecting and chopping blade and logarithmic spiral supporting disc blade and slide-cutting angle of the logarithmic spiral supporting disc blade had the obvious effect. Based on the actual operation conditions and theoretical analysis, the rotation speed of collecting and chopping blade, transmission ratio between collecting and chopping blade and the logarithmic spiral supporting disc blade and slidecutting angle of the logarithmic spiral supporting disc blade were selected as the test factors, and the peak straw breaking force, slide-cutting energy consumption and slidecutting momentum were selected as the test indexes. A Box-Behnken test was executed based on the finite element analysis method because the peak straw breaking force and slide-cutting momentum in actual field experiment was impossible to be measured. The results showed that the primary and secondary factors that affected the peak straw breaking force, slidecutting energy consumption and slidecutting momentum was transmission ratio, slidecutting angle of the logarithmic spiral supporting disc blade and rotational speed of the collecting and chopping blade. When the rotational speed of the collecting and chopping blade. slidecutting angle of the logarithmic spiral supporting disc blade and transmission ratio were 1950 r/min, 40°and 0.5, which was the optimal parameter combination, the peak straw breaking force, slidecutting energy consumption and slidecutting momentum were 101.71N, 1049.42W and 0.032N·s, respectively. The field validation experiment results showed that the slide-cutting energy consumption was 1150.43 W, the error with the model predicted value was 9.63% and the maize straw chopping pass ratio was 93.34%, which satisfied with the national standard. The research can provide references for the design and optimization of the maize straw chopping machine.