Abstract: A testing apparatus for the hydrostatic interlock of a lifeboat includes a pressure cylinder provided with a valve. A positive-negative pressure annular fastener made of soft plastic material is assembled on the topside of the pressure cylinder and has its topside formed with an attaching surface. A U-shaped support frame is fixed at the outer side of the pressure cylinder, and a telescopic support holder is connected to the U-shaped support frame. An anchor base is positioned under the telescopic support holder, and a manual pump has a tube connected to the valve, and installed with a pressure gauge. The testing apparatus for the hydrostatic interlock of a lifeboat in the invention can simulate the launchings pressure of a lifeboat to carry out actual hooks release in a lifeboat drill, able to ensure safety of lives of the personnel who participate in the drill.