Preparing method for sweet potato flour

The invention discloses a preparing method for sweet potato flour. The preparing method includes the following steps that sweet potatoes are cleaned, washed with water and minced through a machine after a period of time, the minced sweet potatoes are put on filter cloth, the filter cloth is bound and put into a container with water to be soaked, then the sweet potatoes in the filter cloth are ground on the container, sweet potato juice obtained after grinding can enter the container and be soaked by the water in the container, the sweet potato juice flows into the container to the maximum, and after completely precipitating, the sweet potato juice is taken, aired and ground to obtain the sweet potato flour. The obtained sweet potato flour is high in quality, and the preparing steps are clear and easy to complete.