Disclosed is a high-pressure gas compressor pressure regulating method. A pressure regulating system comprises a gas compressor and a main gas pipeline, the main gas pipeline is connected to a gas inlet of the gas compressor, a gas outlet is arranged on the gas compressor and is connected to a subsequent gas turbine generator set through the gas pipeline, the gas outlet connected with the gas compressor is further provided with a bypass pipeline, one end of the bypass pipeline is connected to the gas outlet of the gas compressor, the other end of the bypass pipeline is connected to the main gas pipeline, a gas cooler and a pressure reduction adjusting valve are sequentially arranged on the bypass pipeline of the gas outlet connected with the main gas pipeline and the gas compressor, and the gas cooler and the pressure reduction adjusting valve are respectively connected into the bypass pipeline. Cooled gas with reduced pressure is returned to an inlet pipeline of the gas compressor by the aid of the cooler and the bypass pressure reduction adjusting valve. The outlet pressure of the gas compressor is dynamically traced and adjusted at any time, and operating stability of the subsequent gas turbine generator set can be sufficiently ensured.