The invention discloses a device for distributing thin cylindrical workpieces one by one, which comprises a slide block, a guiding block and a slide block driving mechanism, wherein the guiding block is provided with a sliding chute; the slide block is arranged in the sliding chute in a sliding way; the slide block is in transmission connection with the driving mechanism; the slide block is provided with a transfer channel which is vertical to and runs through the side wall of the sliding chute; the side wall of one side of the sliding chute is provided with a workpiece inlet channel and a compressed air inlet channel; one side of the slide block corresponding to the compressed air inlet channel is provided with a step; the convex surface of the step is tightly attached to the side wall of the sliding chute; a horizontal plane, vertical to a movement direction, of the transfer channel coincides with a transitional surface of the step and the horizontal plane is no higher than a split of the transfer channel; a gap is reserved between a section above a horizontal plane of the slide block and the side wall of the sliding chute; a distance from a concave surface of the step to the side wall in which a push-off channel of the sliding chute workpieces is arranged is smaller than the minimum possible length of the workpieces; and a distance from the convex surface of the step to theside wall in which the push-off channel of the sliding chute workpieces is arranged is greater than the maximum possible length of the workpieces.