The utility model relates to the technical field of building machinery, and provides a
drill bit of a rotary drilling rig, which comprises a
drill cylinder with a cavity, an opening at the bottom of the
drill cylinder, a plurality of drill teeth circumferentially arranged at the edge of the opening at the bottom of the drill cylinder, a top plate arranged at the top of the drill cylinder, a connecting component arranged above the top plate, and a clamping component arranged on the inner wall of the drill cylinder. The clamping
assembly is used for clamping and fixing the
rock breaking assembly, the
rock breaking assembly comprises a
rock breaking power piece, the output end of the rock breaking power piece faces the bottom of the drill
barrel and is used for breaking a
rock core, the rock breaking assembly is detachably arranged on the inner wall of the drill
barrel through the clamping assembly, and the rock breaking power piece is arranged to be an oil hammer. The axis of the output end of the oil hammer is parallel to the axis of the drilling
barrel, a gap is reserved between the top plate and the drilling barrel, reinforcing ribs connected with the inner wall of the drilling barrel are arranged on the top plate, and the connecting assembly comprises a connecting shaft used for being connected with a drilling rod. According to the utility model, the
rock core entering the
drill bit can be continuously vibrated, so that the
rock core is broken, and the hole digging efficiency of the
drill bit is improved.