The invention discloses a wall polishing device for building construction. The device comprises a mounting plate, handles are fixedly connected to the top and the bottom of the mounting plate, a caseis fixedly connected to the right side face of the mounting plate, a first purifying box and a second purifying box are fixedly connected to the top and the bottom of the case respectively, and communicating grooves are formed in the joints of the case, the first purifying box and the second purifying box. Through arrangement of the mounting plate, the case, the first purifying box, the second purifying box, a driving motor, a driving shaft, a grinding disc, a first driving wheel, a second driving wheel, a fixed bearing, a first driven wheel, a second driven wheel, a first conveying belt, a second conveying belt, dust collecting fan blades, a first air filtering net, a second air filtering net and an air purifying net which are matched with one another, the purpose of purifying air in a polishing area is achieved, and the problem that when an existing wall polishing device for building construction is used for polishing, large dust is generated and the body health of operators is affected is solved.