Abstract: Analyzing the interaction of straw-soil-machinery and clarifying the movement and distribution of straw plays an important role in straw management and optimal design of farming machinery. Design-Expert software and Box-Behnken test were used to conduct an experimental study on the performance of key operation parameters under the interaction of straw-soil-rotary tiller on straw displacement and burying effect. In the tillage experiment, a quadratic regression orthogonal experiment was designed with three factors and three levels, including the influencing factors of the straw length, the tillage depth, and the rotary speed, and the response indexes of straw displacement and burial rate. By establishing the response surface mathematical model, the effects of various factors on the performance of rotary tillage were analyzed. The experimental results showed that the significant order of the influence on the amount of straw burial rate and straw displacement was as follows: the tillage depth, the straw length, and the rotary speed. The interaction between the tillage depth and the straw length had a significant impact on the straw burial rate and straw displacement, while the interactions between other parameters were not significant. When the straw length was 5 cm, the tillage depth was 14.99 cm and the rotary speed was 320 r/min, the straw returning effect was the best. The corresponding indexes of straw burial rate and straw displacement were 95.5% and 27.6 cm, respectively. The optimized parameters were used for experimental verification. The straw burial rate and straw displacement were 93.3% and 28.1 cm, respectively. The results can provide reference for the adjustment of operation parameters of rotary tillage and provide theoretical support for the study of straw-soil-machine interaction mechanism.