Anchor hammer for cubic press

The anvil comprises an anvil core body, a pre-tightening cavity steel ring and an auxiliary pressing frustum ring body, a pre-tightening cavity is formed in the pre-tightening cavity steel ring, the pre-tightening cavity is composed of a downward pressing frustum cavity, an auxiliary pressing frustum cavity and a tail end ring cavity which are communicated in sequence, the anvil core body is inserted into the downward pressing frustum cavity, and the auxiliary pressing frustum cavity is formed in the tail end ring cavity. The holding-up hammer core body is formed by integrally connecting a tetrahedron, a connecting cone body and a downward pressing frustum body, the side faces of the tetrahedron are four ladder faces, the top face of the tetrahedron is a square face, a threaded hole is formed in the bottom of the downward pressing frustum body, the auxiliary pressing frustum ring body is arranged in the auxiliary pressing frustum cavity, and the auxiliary pressing frustum ring body is connected with the conne