The invention discloses an energy-saving shield machine hydraulic pressure control system, adopting hydraulic transformer, which comprises a hydraulic transformer, a motor, a constant pressure variable displacement pump, a two-position three-way reversing valve, a proportional overflow valve, a safety valve, an accumulator, a hydraulic cylinder, a three-position four-way reversing valve, a hydraulic motor, a reducing valve and a two-position two-way reversing valve; wherein, the shield machine driving, the cutter head drive and the spiral transportation system are integrated in a loop; the constant pressure network comprising the constant pressure variable displacement pump and the accumulator provides the system with power energy; the propulsion system adopts group control and comprises a plurality of groups; the discharge capacity of variable displacement pump/motor inside the hydraulic transformer is adjusted in real-time to control the speed and the propulsive force of the propulsion hydraulic cylinder and the rotational speed and the output torque of the hydraulic motor. The energy-saving shield machine hydraulic pressure control system has the advantages of adopting hydraulic transformer and other energy-saving elements and control methods, lossless transfer of energy, guarding against energy loss in the throttling speed regulation system, and good performance of energy-saving.