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Considering most of the present combined machines of rotary and subsoiling usually place subsoiling components in front of rotary components, without the research of interaction between these two working components, based on the interaction between subsoiling and rotary tillage components, a combined tillage implement of reverse-rotary and subsoiling for deep ploughing was designed and developed. The overall implement aimed at deepening the working depth, improving the working quality and reducing tillage resistance, with focus on the interaction research of the process of rotary tillage and subsoiling components. Whole implement parameter was optimized by discrete element method (DEM), orthogonal experiment and finite element analysis (FEM) simulation. As indicated in the results of simulated orthogonal experiment, working quality was the best when operation speed was 1.8km/h, rotary speed was 350r/min, rotary blade type X was IIT195, in which case particle amount of heap soil quantity was 5283, straw coverage was 98.37%;the results of DEM demonstrated that the strength met the working requirements. Field test based on optimal parameters showed that rotary tillage depth was 182.8mm, subsoiling depth was 388.4mm, surface flatness was 18.3mm and soil bulkiness was 17.22% for the combined tillage implement of reverse-rotary and subsoiling;rotary tillage depth stability, subsoiling depth stability and straw coverage were all beyond 90%, which completely met the soil preparation requirement in deep layer. Compared with combined subsoiling and rotary cultivator, this combined tillage implement of reverse-rotary and subsoiling had better consistence of working depths, higher vegetation coverage and the tillage resistance was reduced by 16.21% under qualified working quality, and it had high working stability and reliability. The development of this implement can provide reference for deep layer cultivation and tillage resistance combined cultivator in arid areas of North China.