The invention discloses an impact bit, and belongs to the technical field of oil and gas drilling engineering. The impact bit comprises an out cylinder, a bit crown, a rotating power assembly and a torsion impact assembly, wherein the rotating power assembly and the torsion impact assembly are sequentially arranged in the outer cylinder from top to bottom; the torsion impact assembly comprises ananvil block body, a hammer body and a valve body which are arranged from outside to inside in sequence; an annular cavity is formed between the outer wall of the valve body and the inner wall of the hammer body and divided into a high-pressure cavity and a low-pressure cavity; an inner cavity of the valve body communicates with the high-pressure cavity, the inner wall of the anvil block body is provided with a plurality of grooves, and a plurality of working cavities are formed between the multiple grooves and the outer wall of the hammer body; second bulges are arranged on the positions, corresponding to the grooves, of the outer wall of the hammer body in the radial direction of the hammer body correspondingly; the high-pressure cavity communicates with one of the working cavities, and the low-pressure cavity communicates with the other working cavity; and the rotating power assembly provides rotating power for the valve body. When the impact bit works, the high-frequency torsion impact effect can be generated on the bit crown, and the phenomena of stick slip and intermittent drill sticking generated during rock breaking through the bit are avoided.