The invention discloses a high-pressure jet grouting 
pile drill bit based on road and bridge construction application. The high-pressure jet grouting 
pile drill bit comprises a rod body and a conicalhead, wherein the rod body is of a cavity structure, and a 
slurry conveying 
pipe is arranged in the cavity; a movable 
assembly is further arranged in the cavity of the rod body, a plurality of 
drill blades are further arranged on the circumferential outer wall of the rod body, when the movable 
assembly moves in the direction of the conical head, the movable 
assembly can push the drill blades to move in the direction away from the rod body, and baffles are arranged on the side walls, facing the conical head, of the drill blades; and telescopic pipes are further arranged in the cavity of the rodbody, one ends of the telescopic pipes communicate with the 
slurry conveying 
pipe, a connector is arranged at the other ends of the telescopic pipes, 
sprayer assemblies as many as the drill blades are further arranged on the circumferential outer wall of the rod body, one ends of the 
sprayer assemblies face the drill blades, and the other ends of the 
sprayer assemblies are located in the cavity of the rod body. According to the high-pressure jet grouting 
pile drill bit, the 
diameter of a pile hole drilled through the 
drill bit can be adjusted, different use requirements are met, meanwhile, itis guaranteed that in the downward drilling process of the 
drill bit, mud and stone in soil can be prevented from blocking the 
slurry conveying 
pipe, and therefore the construction efficiency is improved.