Impact hammer for cast-in-place pile

The invention relates to an impact hammer for a cast-in-place pile. The impact hammer comprises a hammer body and hammer tooth assemblies; the hammer body comprises a body, a plurality of wing parts and wing feet; the multiple wing parts are all fixedly connected with the body and evenly arranged in the circumferential direction of the body; the wing feet and the wing parts are the same in number,and the wing feet are formed by extending in the circumferential direction of the body from the wing parts; cavities are formed between the adjacent wing parts and the body; the hammer tooth assemblies correspond to the wing feet one to one; the hammer tooth assemblies are arranged at the end of the hammer body and comprise a plurality of first hammer teeth, a plurality of second hammer teeth anda plurality of third hammer teeth, and the first hammer teeth, the second hammer teeth and the third hammer teeth are arrayed in a staggered mode; and in the central axis direction of the body, the length of the first hammer