Rustproof device for anchor bolt of rubber dam

The utility model discloses an anti-rust device for a rubber dam anchor bolt, which relates to the technical field of bolt construction and comprises a bolt, a nut, a tight closing sleeve and a threaded positioning sleeve. The bolt penetrates through the fastener and then is fixed by the nut, the bolt and the nut are completely covered by the tight closing sleeve, the tight closing sleeve is in tight contact with the fastener, and a threaded positioning sleeve is arranged at the position, corresponding to the bolt, of the top end in the tight closing sleeve. A sealing rust-proof assembly for blocking water flow and air and a positioning assembly for assisting positioning installation are arranged on the inner wall of the tight closing sleeve in an attached mode. According to the anti-rust device for the bolt, the sealing anti-rust assembly and the positioning assembly cooperate with each other, under the action of three protective layers formed by the first expansion ring, the second expansion ring and the in