Integrated drill bit for deep large-particle-size pebble geological variable-diameter pile construction

The utility model discloses an integrated drill bit for deep and thick large-particle-size pebble geological variable-diameter pile construction, which is detachably connected to the bottom of a drill rod of a rotary drilling rig and comprises a large-diameter drill bit, a small-diameter drill bit and a traction device, the small-diameter drill bit is sleeved with the large-diameter drill bit, and the traction device is connected with the large-diameter drill bit. The top of the small-diameter drill bit is detachably connected with the bottom of the drill rod; the top of the large-diameter drill bit is fixedly provided with a sliding hoop, the sliding hoop is detachably connected with the bottom of the drill rod, and the diameter of the sliding hoop is adjustable so as to clamp or release the drill rod; the traction device is arranged on the rotary drilling rig and used for pulling the sliding hoop and the large-diameter drill bit to slide along the drill rod. Reducing pile construction can be achieved withou