Abstract: Aiming at the problems of hydraulic cylinder leakage and friction between piston and cylinder body of 30 MN hydraulic force standard machine, based on the systematic summary of relevant research and application experience at home and abroad, a new type of hydraulic cylinder mechanism was innovatively designed, and double oil circuit control technology was introduced. Through the above technical improvements, the control performance of the equipment was effectively improved, and finally the sensitivity and repeatability of the hydraulic force standard machine reached the level of one in ten thousand.