The invention relates to the technical field of fans, and discloses an industrial large fan with a fan blade floating dust cleaning function, the industrial large fan comprises a mounting column and a driving motor below the mounting column, a rotating shaft frame is mounted at the lower end of the driving motor, a mounting shaft is arranged at the lower end of the rotating shaft frame, and a connecting sleeve is mounted on the outer side of the mounting shaft; a fixing hole is formed in the lower surface of the mounting shaft, an inserting pin groove is formed in the outer side of the connecting sleeve, a flat fan blade is mounted in the inserting pin groove, and the flat fan blade and the inserting pin groove are fixed through an inserting flat pin. When the mounting shaft drives the flat fan blades to rotate, large centrifugal force can be generated to pull the sliding sleeve towards the outer side, the outer sides of the flat fan blades are swept while pulling is conducted, when rotation stops, the sliding sleeve is pulled back through the contraction spring, sweeping treatment can be conveniently conducted next time, through the structure, the sweeping function of the device can be achieved, and the sweeping efficiency is improved. The structure is simple to operate, and manual interference is not needed.