A dustproof type concrete prefabricated block drilling device for building construction comprises a supporting frame, a driven shaft is arranged on the supporting frame in a vertical sliding manner, a cam is fixedly mounted on the driven shaft, a drill bit is vertically arranged at the bottom end of the driven shaft, a wedge block is fixed to the right end of a first sliding rod, the left end of a first limiting spring is fixed to a sleeve on the right side of the driven shaft, and a roller is in abut joint with the wedge face of the wedge block; a right cover plate is hinged to a dust suction pipe, and is located in a dust suction box, a left cover plate is hinged to a dust exhaust pipe, and is located outside the dust suction box, an air suction sleeve is arranged on the dust suction box and communicates with the dust suction box, dust generated during drilling of the dust suction pipe is conveyed to the dust suction box, a piston rod drives a water drawing piston head to vertically move in a reciprocated manner, tap water is sprayed to the drill bit and a concrete prefabricated block through a spraying head, the dust falling and removing effect is further achieved, and the drill bit is subject to water cooling; the temperature of the drill bit is effectively reduced, and the drilling quality is improved.