The invention discloses a method for using a high-pressure rotary jet grouting pile nozzle for road and bridge construction. The high-pressure rotary jet grouting pile nozzle comprises a rod body anda conical head, wherein the rod body is internally of a cavity structure, a grout conveying pipe is arranged in the cavity, a moving assembly is also arranged in the cavity of the rod body, the circumferential outer wall of the rod body is further provided with a plurality of drill blades, when the moving assembly moves towards the conical head, the moving assembly can push the drill blades to move in the direction away from the rod body, baffles are arranged on the side walls, facing the conical head, of the drill blades, stretchable pipes are further arranged in the cavity of the rod body, one ends of the stretchable pipes communicate with the grout conveying pipe, the other ends of the stretchable pipes are provided with joints, the circumferential outer wall of the rod body is furtherprovided with nozzle assemblies with the number same as the number of the drill blades, one ends of the nozzle assemblies face the drill blades, and the other ends of the nozzle assemblies are locatedin the cavity of the rod body. According to the method, the diameter of a pile hole drilled by the drill bit can be adjusted, then different use requirements can be met, meanwhile, it is guaranteed that in the drilling-down process of the drill bit, mud and stones in soil can be prevented from blocking the grout conveying pipe, and the construction efficiency is improved.