Abstract: To improve the mechanization and reduce the labor intensity of manual topping in hilly tobacco growing areas, the shear mechanical properties of apical bud stalks during tobacco topping were investigated. Apical bud stalks of tobacco cv. Qinyan 96 were selected as the research object. The effects of cutting edge shape, cutting edge angle and shearing speed of the shearing blade on the shearing force were analyzed by a single-factor experiment. Finally, the determined parameters of shearing blade, blade edge angle and shearing speed were single edge, 10° and 40-60 mm/min, respectively, which were suitable for shearing apical bud stalks. Taking the shearing mode, blade shape and shearing speed as the influencing factors and the shearing force as the index, an orthogonal experiment with three factors and three levels was set up using Design-Expert software. The results showed that when the shearing mode was sliding shear, the blade shape was an arc blade, and the shearing speed was 50 mm/min, the shearing force required to shear the apical bud stalks of tobacco plants was lower.