The high-pressure fire resistant oil system uses phosphate-based fire resistant oil as a working medium, applied in DEH hydraulic pressure control in large-scale thermal generators. This includes theoil supply system, actuator, and emergency trip system. The oil supply system’s function is to provide high-pressure fire-resistant oil which is used to drive the servo actuator. The actuator responds to the electric command signal coming from the DEH to regulate the degree of opening of the steam turbine’s steam valves. The emergency trip system is controlled by the steam turbine’s trip parameters. Once these parameters exceed their operating limit, the system will shutdown all the steam turbine’s steam inlet valves, or close only the regulation air valves. The system’s characteristics are high-oil ignition, fast dynamic actuator response, large lifting force, and high control accuracy.