Bicycle hub waterproof structure

The invention discloses a bicycle hub waterproof structure. A ratchet wheel is in screw joint with the side of a hub body. A mandrel is arranged on the inner side of the hub body. A ball is arranged on one side of the mandrel. A ball bowl is arranged on the outer side of the ball. A waterproof cover is arranged on the side of the ball. A first pre-pressing part is installed on the inner side of the waterproof cover. The ratchet wheel is installed on the side, away from the ball, of the mandrel. A rolling shaft is installed on the outer side of the ratchet wheel. A second pre-pressing part is installed on the inner side of the rolling shaft. An iron oil seal is arranged on the outer side of the rolling shaft. A rubber oil seal is installed on the side of the second pre-pressing part. External water impact is buffered through the rubber oil seal, the buffered water makes contact with the iron oil seal to reduce the pressure, the good waterproof performance is achieved, through tight connection of structures of