The invention discloses a dust collecting device for teaching. The dust collecting device for teaching comprises a chalk sleeve. The chalk sleeve comprises a shell, internal threads, threaded silica gel, a screw rod and a dust collecting device body. The shell is of a long strip hollow structure, and comprises a first shell part and a second shell part connected end to end in a length direction of the shell; the internal threads are arranged on inner side walls of the shell; the threaded silica gel and the internal threads are in mosaic distribution and distributed on the inner side walls of the shell; the screw rod is in threaded connection with the shell; the dust collecting device body is a long strip slot body with an opening on the upper end, and is horizontally arranged on a writing face of a blackboard; two ends of the dust collecting device body are in sliding connection with two side edges of the blackboards; and the surface of the dust collecting device body and the blackboard have the same color. According to the dust collecting device for teaching provided by the invention, the chalk sleeve used for fixing a chalk to write in a sleeving way is provided for a user, so that a hand of the user cannot be polluted; and in addition, the dust collecting device body can synchronously collect scattered chalk dust while the user is writing, so that pollution cannot be caused to the indoor environment.