The invention discloses a sweet potato starch extraction device. The extraction device comprises a frame body, a grinding crushing device, a smashing device, an anti-blocking mechanism, a screening removing device, a stirring crushing device, a receiving hopper and a forming device; multiple rows of teeth are arranged in the grinding crushing device, so that the grinding crushing speed of sweet potatoes is guaranteed, working is continuous, and the working efficiency is improved; the ground and crushed sweet potato blocks enter the smashing device, are smashed and then enter the screening removing device; and through filtering of the screening removing device, sweet potato pulp is directly recycled into the forming device through the receiving hopper, small-particle sweet potato chips enter the stirring crushing device to be processed again and then are output into the forming device to be subjected to starch extraction, interference of the external environment is avoided, and the product quality is high. According to the extraction device, sweet potatoes are thoroughly smashed through multiple processes, the maximum starch extraction amount is achieved, the automation effect is sufficient, and the problems of low automation degree and starch quality of manual operation are solved.