Abstract: In order to provide a reasonable and accurate design for mechanized harvest of hydroponic leafy vegetables and reduce production cost，Brassica parachinensis was selected as the object.Taking type of cutter，cutting speed，and variety of Brassica parachinensis as independent variable and shear strength as response index，stem cutting experiment were carried out by single factor and orthogonal experiment methods，and factors and their interaction were analyzed.Single factor analysis showed that variety，cutter type and cutting speed had significant effects on maximum shear strength，and cutting speed was the greatest one.Results of orthogonal experiment of mixing level showed that interaction between variety and cutting speed was significant，and the level was the highest.The best experimental combinations were Qingye sharp leaf cabbage，oblique knife and cutting speed 12 m/min.These results could provide a theoretical basis for design of cutting device.