Vibrating screen grading method for pine nuts

The invention discloses a vibrating screen grading method for pine nuts. The vibrating screen grading method for the pine nuts comprises the following steps: winnowing the pine nuts during a raw material lifting process to blow away a part of impurities in the pine nuts at first, and then conveying the winnowed pine nuts into a vibrating screen and grading, wherein the vibrating screen comprises multi-stage screen cloths with meshes which are gradually reduced from top down, silica gel bouncy balls are placed between every two adjacent layers of screen cloths, during a process of screening the pine nuts through the vibrating screen, the pine nuts with small particle sizes fall onto the next layer of screen cloth through the meshes of the previous layer of screen cloth, and are conveyed with the vibrating screen along a direction from a charge port to a discharge port, and the pine nuts realize grading among the multi-layer screen cloths. In the vibrating screen grading method for the pine nuts, which is disclosed by the invention, through reasonably designing the vibrating screen and the bouncy balls, the bouncy balls are uniformly distributed between the screen cloths at the two sides during a vibrating process, and co-vibrate with the vibrating screen, thus the screening efficiency of the pine nuts is greatly increased; the screened pine nuts are uniform in size; and silica gel is high in toughness and free from breakage during the vibrating so as to ensure no secondary impurities in the screened pine nuts.