In order to improve peanut sheller's shelling and cleaning efficiency, this thesis chooses the scraper shelling device on the basis of studying other peanut shellers. And it also determines the overall scheme design of sheller and introduces the scraper structure and working principle of the peanut sheller. It puts its focus on the peanut sheller's transmission structure design, which includes the choice of actuator components, V belt, V belt wheel design, design of the main shaft and parameters calculation, bearing and the choice of key. Through the optimization of gear design, the work efficiency and stability of the peanut sheller are improved further.