This paper designed a kind of Self-Propelled Pepper Harvester, it introduced the whole structure and working theory, determined the structural parameters of key parts such as picking device, cleaning device, analysed the Mechanism of picking and cleaning, determined the Suspension speed of pepper and leaf. The experiment proves that while the moving speed is 5.3km/h, the rpm of fillip roller is 210r/min, the space between star discs and star axles is 200-220mm, the rpm of star axle is 210 r/min, the airflow speed is 5-8m/s,the picking ratet is 97.1%, the rate of impurities is 9.8%, the mechanization of the harvesting peppers is achieved.