The invention discloses a rapid classifying device for urban garbage. The device comprises a garbage can body, wherein a protecting cover is welded to the outer wall of one side of the garbage can body, and a motor is connected to the inner wall of the bottom part of the protecting cover through a screw; an inlet is formed in the middle of the outer wall of the top end of the garbage can body; twobaffle plates are welded to the middle of the inner wall of the top part of the garbage can body, and the two baffles are symmetric with respect to a central axis of the inlet; a telescoping cylinderis fixed to one side of the inner wall of the top part of the garbage can body through a screw; a vertical connecting rod is welded to the bottom end of the telescoping cylinder; and a hinge pin is inserted into the bottom end of one side of the connecting rod. The device is simple in structure; a first extruding roller and a second extruding roller are capable of extruding and crushing garbage through the motor, so that the size of the garbage can be reduced, and as a result, the storing capacity of the garbage can body can be improved; and cleaning people do not clean frequently, so that the workload of the cleaning people is decreased.