The invention relates to the technical field of bottom clearing equipment for dry operation cast-in-situ bored piles, in particular to an air-flowing type bottom clearing device for a dry operation cast-in-situ bored pile. The air-flowing type bottom clearing device for the dry operation cast-in-situ bored pile comprises a barrel body (1), motors (2), an air duct (3), a machine base (7), stirring bars (9), soil baffles (10) and connectors. The air-flowing type bottom clearing device for the dry operation cast-in-situ pile is characterized in that the barrel body (1) is composed of a cone-shaped tube, a cylinder tube and a spherical base; according to the barrel body (1), one end of the cylinder tube is provided with the cone-shaped tube, and the other end of the cylinder tube is provided with the spherical base; according to the barrel body (1), the machine base (7) is arranged in the portion where the cylinder tube and the spherical base are connected; the soil baffles (10) are arranged on one side of the machine base (7) in the barrel body (1); the motors (2) are evenly distributed on the machine base (7); key grooves are formed in one side of the tail end of a spindle of each motor (2); and one end of the spindle of each motor (2) penetrates through the machine base (7) and the thin wall of the spherical base of the barrel body (1) sequentially.