Grain screening equipment with complete dedusting function

The invention discloses grain screening equipment with a complete dedusting function. A feeding opening communicating with a storage bin in a main shell is formed in the middle of a spreading platformat the top of the main shell. An air guide cavity annularly distributed around the feeding opening is formed in the spreading platform. A spiral feeding mechanism is located at the feeding opening and is used for feeding grain from the storage bin. First air guide holes communicating with the air guide cavity are formed in the side wall of the spiral feeding channel. The spreading mechanism is located above the spiral feeding mechanism and is connected with the spiral feeding mechanism. The grain screening equipment with the complete dedusting function is reasonable in structural design; grain meeting the granularity requirements is conveyed to the spreading platform through the feeding mechanism so as to be screened; and in the discharging process, dust adhering to the grain is sucked away by the feeding mechani