The utility model provides a power square shell battery formation negative pressure suction nozzle which comprises a negative pressure pipeline, a liquid injection port and a battery cover plate, thebottom of the negative pressure pipeline is connected with the liquid injection port, and the connecting position of the negative pressure pipeline and the liquid injection port is connected with thebattery cover plate. The utility model provides a negative-pressure suction nozzle for formation of a power square-shell battery, which can directly suck out formation overflowing electrolyte withoutdepositing at a liquid injection port, solves the problem of helium leakage in subsequent sealing welding, prevents the negative-pressure suction nozzle from enabling the electrolyte to be connected with a negative-pressure suction nozzle sealing ring, and reduces the cleaning frequency of the sealing ring. The utility model has the advantages of simple structure, stable performance and longer service life.