Pre-cooling water ring capable of automatically cleaning impurities

The invention discloses a pre-cooling water ring capable of automatically cleaning impurities. The pre-cooling water ring comprises a connecting ring, a guide post, an outer ring, two sealing rings, an inner ring, an elastic piece, a screw and a water nozzle. One end of the guide post is fixedly connected with the outer ring, and the other end of the guide post is in threaded connection with the connecting ring. The inner ring is embedded into the inner circle space of the outer ring, the screw connects the inner ring with the outer ring from bottom to top, and the elastic piece is arranged between the screw and the inner ring which are connected. An upper annular sealing space, a lower annular sealing space and an annular space between the two sealing spaces are arranged at the lower endof the surface, connected with the outer ring, of the inner ring, and the two sealing rings are correspondingly arranged in the two annular sealing spaces. An air inlet is formed in any section of thering section at the low e