In order to solve the problem that the hydraulic transformer in the constant voltage secondary regulation loop is difficult to adjust its output flow in time due to load changes, based on the full study of the hydraulic transformer, a variable pressure energy saving and real-time flow regulation is proposed for the variable pressure energy-saving flow commutator. The application range of the hydraulic transformer was further expanded, and AEMSim was used to study the key technologies of the flow regulation response characteristics when the load changed. The results show that the flow commutator has good sensitivity and stability, and it increases the response time when the load is stepped to about 0.11 s.