Abstract: Abstract: Sweet potato is an important food crop and can also be used as raw material for foodstuffs, animal feed and raw materials for renewable energy. Furthermore, research shows that it has anti-cancer effects. As sweet potato vines are long and difficult to be separated. The vines cleaned up before sweet potatoes harvest has a great role in promoting to improve the quality of sweet potato and the sweet potato harvest efficiency. In order to alleviate the shortage of sweet potato vines crushing machine in the hilly areas of China, the walking sweet potato vines crushing machine was designed in this paper. Based on the analysis of the whole structure, we expatiated on the working principle of the sweet potato crushing machine, and analyzed the structure of key components such as crushed parts, anti-wear technology, ground lifting mechanism and transmission mechanism. Before the machine started to work, the ground clearance needed to be adjusted based on the width and height of the ridge. The high ground clearance leaded to the long stubble height and poor operating effect, but the low ground clearance leaded to damage the sweet potato and increase power consumption. Sweet potato vines breaking qualified rate, stubble height and damaging rate were the main indicators of evaluating sweet potato vines crushing machine. The Box-Benhnken central composite experimental design principle was used on the basis of single factor experiment to study the working parameters of walking sweet potato vines crushing machine. The cutter roller speed, the ground clearance and the distance between blades were taken as three factors which influenced the working quality, and a three-factor and three-level response surface experiment was conducted. The mathematical model of the response surface was established, and the influence of each factor on the machine quality of the operation was analyzed and optimized. The result showed that when the roller rotation speed was high, the ground clearance was small and there was a moderate distance between blades. As such, the overall impact trend of the vines breaking quality rate was high and the stubble heights was low. When the roller rotation speed was small, the ground clearance was high and there was a moderate distance between blades, and the overall impact trend of the rate of the damage was small. The experiment results also showed that the order of the factors affecting of the vines breaking quality rate was: roller rotation speed >ground clearance >distance between blades The order of the main factors affecting of the stubble heights was: ground clearance >roller rotation speed >distance between blades The order of the main factors affecting of the rate of the damage was: ground clearance >roller rotation speed >distance between blades. In 2016, a three-time repeated test for verifying the exactness of the model was conducted on the Nanjing Research Institute for Agricultural Mechanization Ministry of Agriculture of Baima testing site. The field test showed that the optimum parameters were: 1950 r/min for the rotation speed, 25 mm for the ground clearance and 40 mm for the distance between blades, 94.88% for the rate of vines breaking qualified rate, 47.08 mm for the stubble heights, and 0.23% for the rate of damage. By comparing the mathematical model and the experimental result, the error was less than 5%, which meant that the model established was reliable and could be used for optimization. The results can provide a reference for the structural design and optimization of the operating parameters of the walking sweet potato vines crushing machine.