Abstract: The paper describes the determination of hydraulic dynamometer torque measurement. The method of huge torque measurement is provided. The principle of torque forced on the hydraulic dynamometer obtained from controller is analyzed in mechanics degree. The steps for torque calibration are displayed in detail. The whole approach is proved through the measurement and calibration data of a certain type of hydraulic dynamometer. The results show that it can be used in torque measurement for hydraulic dynamometer of low velocity and huge power. The accuracy satisfies the country standard on hydraulic dynamometer.