The invention relates to a teaching tool device, in particular to a dustproof blackboard eraser in order to prevent the dust produced during blackboard erasing from flying everywhere. The dustproof blackboard eraser is composed of a rectangular ordinary blackboard eraser and a cuboid miniature dust collector. According to the specific design, a dust inlet is formed in the periphery of the rectangular blackboard eraser, a surrounding edge is arranged on the periphery of the dust inlet, dust is prevented from flying everywhere, chalk dust is made to enter the dust inlet, the cuboid dust collector is arranged on the rectangular blackboard eraser and communicated with the dust inlet, chalk dust can be effectively sucked in, and a dry battery serves as the power supply of the dust collector. The dustproof blackboard eraser has the advantages of being simple in structure, convenient to use and remarkable in dustproof effect.