A dustproof structure for a sleeve bearing includes an axial tube, a sleeve bearing, a dustproof cushion and a motor rotor. The motor rotor has a shaft seat and a shaft mounted thereto. The axial tube accommodates the sleeve bearing which bears an axial hole through which the shaft of the motor rotor is freely extended. The dustproof cushion is mounted in the axial tube and attached to an end surface of the sleeve bearing to prevent from entering foreign dust. An axial thickness of the dustproof cushion is used to compensate a clearance formed between the sleeve bearing and the shaft seat, and a diameter of the dustproof cushion is smaller than an outer diameter of the shaft seat to prevent from precipitation of dust on the sleeve bearing.