The invention discloses a salvage device and a construction method of a drill bit of a spin dig drill. The salvage device comprises a comb-shaped rotating drill bit, a flat bamboo cutting type drill,and an anchor type drill bit; and in the comb-shaped rotating drill bit, the lower end of a first high pressure water pipe is connected with a rotating drill bit barrel body, radially distributed rotating drill bit irons nail or elastic steel wire are arranged on the inner wall or the outer wall of the rotating drill bit barrel body, the top end of the first high-pressure water pipe is connected with a drill pipe, and water outlet holes are formed in the side wall or / and bottom of the rotating drill bit barrel body. During construction, the comb-shaped rotating drill bit removes drilling slagon the drill bit of the spin dig drill, and the drill bit of the flat bamboo cutting type drill removes attachment in the drill bit of the spin dig drill; and the anchor type drill bit lifts the drillbit of the spin dig drill. According to the fishing device and the construction method of the drill bit of the spin dig drill, the drilling slag in a borehole is cleaned in the early stage by the comb-shaped rotating drill bit and the drill of the flat bamboo cutting type drill, a passage in the borehole is unobstructed, and the success rate of drill bit salvage of the spin dig drill bit is greatly increased; and the anchor type drill bit adopts an internal bracing structure, the problem of small gap between the drill bit of the spin dig drill and the inner wall of the borehole is solved, andthe success rate of salvage is significantly increased.