Aiming at the problems of high labor intensity, low operation efficiency and uneven spraying of bud inhibitor in the process of cigar tobacco leaf planting and production, the work process of clamping, shearing, and spraying in turn was proposed. And the knapsack topping and bud suppression machine for cigar tobacco was developed. The machine was mainly composed of synchronous clamping mechanism, shearing mechanism and bud inhibitor spraying device. The mechanical analysis of the synchronous clamping mechanism under stable clamping state was carried out, and the key structural parameters were determined. Combined with the analysis of the structural characteristics of the top bud and the principle of sliding cutting, the key structural parameters of the shear blade were obtained. The spraying device of the bud inhibitor adopted the spraying operation mode of annular jet. According to the internal flow characteristics of the jet nozzle, the range of key structural parameters of the spraying device was analyzed. Based on Fluent software, the single factor simulation test of the nozzle flow characteristics was carried out. It was concluded that when the diameter of the main channel was 5~7mm, the number of nozzles was 5~7, and the diameter of the nozzles was 1~2mm, the fluid velocity between the nozzles was more uniform. The field experiment of spraying device structure optimization was carried out with the pesticide rate of cigar tobacco leaves as the index. The results showed that when the diameter of the main channel was 6mm, the number of nozzles was 6, the diameter of the nozzle was 1.5mm, and the spraying angle was 60°, the pesticide area of cigar leaves was 0.37%. The field performance test results showed that the average top bud cutting rate of the cigar tobacco leaf topping and bud suppression device was 92.40%, the top bud drop rate after cutting was 3.20%. And when the spraying flow rate of the bud suppressor was 25mL/s, the average axillary bud infection rate was 93.75%. The knapsack topping and bud suppression machine for cigar tobacco can complete the process of topping and bud inhibition, and the bud inhibitor was sprayed evenly. The research can provide an approach for the development of cigar tobacco leaves topping and bud inhibition machine.