The invention discloses a dust removing device of a stirring machine with strong practicability for building construction. The dust removing device comprises a bearing plate, wherein a stirring box is arranged at the top part of the bearing plate, the two sides of the bottom part of the stirring box are fixedly connected with supporting legs, the bottom parts of the two supporting legs are fixedly connected with the bearing plate, and the top part and the bottom part of the stirring box are respectively communicated with a feeding hole and a discharging hole. According to the dust removing device disclosed by the invention, by mutual matching of a controller, a first supporting rod, a second supporting rod, fixing blocks, a dust suctioning hole, an air blower, a dust suctioning pipe, a limiting rod, a dust removing box, a dust discharging pipe, a baffle plate, a dust discharging hole, a water tank, bearing rods, a resistance wire, a water filling hole, a steam discharging pipe, a floating block and a monitoring rod, the problem of low practicability of the existing dust removing device is solved; and water steam is adopted for removing dust, and the collected dust such as lime also can be discharged by the dust discharging hole for secondary utilization, so that the dust removal cost is reduced and the energy is greatly saved.