Drill bit of rotary drilling rig

The invention discloses a drill bit of a rotary drilling rig. The drill bit comprises a barrel, a spiral piece and a rotary drill, one end of the barrel body is connected with the drill rod, the spiral sheet is spirally arranged on the barrel body, and an internal thread is arranged on the inner wall of the barrel body; the rotary drill is arranged in the barrel body, external threads are arranged on the rotary drill, and a lifting mechanism connected with the rotary drill is arranged in the barrel body and can drive the rotary drill to move in the axial direction of the barrel body. When the drill bit of the rotary drilling rig is used, the drill bit can be switched during operation under a hole, the drill bit can adapt to different operation environments conveniently, the time for replacing the drill bit is greatly shortened, and the working efficiency is improved. 本发明公开了一种旋挖钻机钻头，包括筒体、螺旋片和回转钻；所述筒体的一端与钻杆相连接，所述螺旋片呈螺旋状设置在筒体上，所述筒体的内壁上设有内螺纹；所述回转钻设置在筒体内，所述回转钻上设有外螺纹，所述筒体内设有与回转钻相连接的升降机构，能够驱动回转钻沿筒体轴向移动。使用上述一种旋挖钻机钻头，