Abstract: In order to avoid the disadvantage of matching power wheel spacing and ridge spacing in onion transplanting operation, a horizontal rotary tiller based on onion transplanter is developed. The rotary tiller is located in front of the transplanting device. The whole machine can complete continuous operations such as furrowing, ridging, transplanting, covering soil and pressing at one time. Rotary tiller adopts integral frame structure and transmission mode of intermediate sprocket to make rotary tillage operation more stable. The main working parts include suspension frame, reducer, rotary tiller shaft, rotary tiller, input shaft, sprocket, chain, etc. The machine uses CAD, SolidWorks, ANSYS and other software for pattern design, 3 D modeling and stress analysis, and focuses on key mechanisms such as rotary tillers. Through theoretical analysis and finite element analysis, the factors affecting the cutting resistance of rotary cutters are determined. Rotary tiller power consumption and maximum stress and deformation position of rotary tiller. The field test results of Hualong scallion test Base in Qingzhou city, Shandong Province showed that the power with the rotary tiller was 35-80 kW, the depth of tillage was 3-18 cm, which satisfied the agronomic requirements of 5-13 cm depth of onion transplanting; The average soil rate is 74.92%, which meets the requirements of rotary tiller design and onion planting.