Automatic gas ventilation and dust falling device

The invention discloses an automatic gas ventilation and dust falling device which comprises a ventilator (1), fan blades (3), a driving assembly (4), a wind blocking assembly (5), a baffle (6) and a dust falling assembly (8). The fan blades are clamped in the ventilator and located at an opening in one end of the ventilator. A cavity is formed in a top plate of the ventilator, the driving assembly and the wind blocking assembly are both embedded in the cavity, the first output end of the driving assembly is in transmission connection with the fan blades, the second output end of the driving assembly is in transmission connection with one end of the wind blocking assembly, and the third output end of the driving assembly is in transmission connection with one end of the dust falling assembly. The baffle is mounted at the opening in the other end of the ventilator, and a ventilation hole (7) is formed in the baffle. The bottom of the wind blocking assembly is movably connected with wind shielding cloth (59), a