The invention provides a friction bank note flattening sorting device. The device comprises a frame, wherein the frame is internally equipped with a bank note spreading flattening mechanism, the bank note spreading flattening mechanism comprises a lower conveying belt horizontally mounted in the frame, the lower conveying belt is equipped with a spreading conveying belt and an upper conveying belt, the spreading conveying belt is close to a hopper mechanism, the upper conveying belt is close to a collection hopper, the spreading conveying belt is obliquely arranged, height of one end of the spreading conveying belt close to the upper conveying belt is smaller than height of one end of the spreading conveying belt away from the upper conveying belt, the spreading conveying belt and the lower conveying belt have an included angle, the upper conveying belt and the lower conveying belt are vertically mounted in a parallel contact mode, the outer surface of the spreading conveying belt is hinged with multiple uniformly-distributed hanging teeth, and the outer surface of the upper conveying belt is provided with multiple uniformly-distributed flexible small teeth. According to the device, a processing problem of wrinkled bank notes is solved, so bank note sorting mechanization is realized, functions are practical, and the wrinkled bank notes are flattened and sorted and are easy for market development and popularization.