The utility model discloses a four-wire ground clamp. The four-wire ground clamp comprises a ground clamp body (21) and a ground terminal (22). The ground clamp body is a cylinder and is annularly provided with four ground cavities, wherein two opposite ground cavities extend to the bottom end of the ground clamp body, and the other two opposite ground cavities extend to the middle of the ground clamp body. Ground hoops (211) are arranged at the ground cavities in the outer wall of the ground clamp body, and the inner walls of the ground hoops are matched with the outer wall of the ground clamp body. The four-wire ground clamp has the advantages that the four-wire ground clamp is suitable for ground leads with the sectional area being over 50 mm<2>; the ground leads are independent of one another and cannot interfere with one another, the grounding requirement of electrical equipment can be better met, a transformer neutral point, a transformer case, a lightning arrester and a down conductor of a JB cabinet can be connected first and then grounded, and the voltage drop of the lightning current on a downlead and an industrial frequency grounding resistor and the residual voltage of the lightning arrester can be prevented from being overlaid on a transformer insulation device so that equipment damage can be avoided; connecting is firm, dismounting and mounting are convenient, and replacing is facilitated.