The shaft power meter can be used to monitor the real torque and power on the ship's propulsion shaft. By measuring the shaft power of the main engine under different working conditions, the matching between hull, main engine and propeller can be understood. When the machine is not matched, the host may not fully use its rated power, and serious overload may occur. With the development of large-scale ships and automation, the efficiency and economy of ships have become important indicators of shipbuilding. As an important means to calculate the conversion efficiency, shaft power measurement has become an important parameter for the ship and the shipowner to accept the newly built ship.