A tail circuit fixing clamp of a three-phase four-wire electric energy meter comprises two clamping plate bodies which are connected through bolts. Eleven grooves are all formed in the opposite faces of the two clamping plate bodies in the length direction of the clamping plate bodies. The numbers from one to eleven are sequentially marked at the positions, right opposite to the grooves, on one of the clamping plate bodies. The tail circuit fixing clamp of the three-phase four-wire electric energy meter has the advantages that the electric energy meter can be replaced rapidly, before an old meter is disassembled, the tail circuit fixing clamp is used for well clamping the ends of tail circuits, the old meter is dismantled, then a novel meter is mounted quickly according to the tail circuit marked numbers corresponding to the number marks on the clamping plate bodies, therefore, the condition of disordered wiring when the electric energy meter is replaced is effectively avoided, the numbers marked with different colors improve wiring efficiency, and the correct connection of the tail circuits is guaranteed.