Abstract: In order to solve the problems of large quantity of corn stover and insufficient depth of returning machine and tools used in production in China, which affected subsequent sowing, emergence quality, high incidence of diseases and insect pests, and “carbon hunger” in deep soil, a kind of straw crushing centralized and full deep returning machine was designed. The machine can complete the operations of picking up, crushing, conveying, deep loosening of trenches, centralized escape and injection burying and crushing of crushed soil at one time. Under the effective reduction of soil disturbance, multiple rows of standing or crushed straw can be buried in a trench with depth of 380～400 mm below the surface. The overall structure and working principle of the straw crushing and centralized full quantity deep return machine were described, and key components such as the straw screw conveyor, the straw discharge fan, the deep loosening and trenching device, and the transmission device were designed and calculated. The rotational speed of the screw conveyor and the straw discharge fan, the size of the discharge port of the straw discharge fan, and the cross-sectional shape parameters of the injection device were preliminarily determined. The flow field inside the straw exhaust fan and the injection chamber was simulated, analyzed and verified. According to the design requirements, the straw chopping centralized full depth return machine was trial-manufactured, and the machine performance and field positioning test were carried out. The results showed that at operation speed of 3 km/h, the straw stalk collecting rate was 90.8%, trenching depth and average straw buried depth was 394 mm and 200 mm, respectively, trenching depth and straw burying depth stability coefficient were 97.4% and 92.5%, respectively, the indicators were in conformity with design value, and satisfied the agricultural requirements. At the same time, the results of field positioning test showed that compared with traditional field, the water storage of 0～200 cm soil was increased by 29 mm, and the contents of organic carbon, total nitrogen and available phosphorus in 20～40 cm soil layer was increased by 7.14 g/kg, 0.59 g/kg and 1.53 mg/kg, respectively. The soil nutrient content and soil fertility and water storage capacity were increased effectively. The method results can provide a scheme and technical reference for the promotion of the technical model of centralized deep returning of straw to the field.