Provided is a gas pressure regulator. The gas pressure regulator comprises a valve body, a pressure regulating assembly and a metal coil. The valve body comprises an air inlet channel, an air outlet channel and a decompression chamber. The metal coil is positioned in the decompression chamber. The pressure regulating assembly comprises a membrane, a moving part and a shielding part. The membrane is positioned in the decompression chamber. The moving part is connected with the membrane. The moving part is provided with a magnetic part which arranged in the metal coil in a penetrating mode. The shielding part is connected with the moving part. The membrane is deformed due to the changes in pressure of a gas source which is connected with the air inlet channel, so that the moving part drives the shielding part to change the opening degree of the air inlet channel, corresponding inductive electromotive force is generated by the movement of the magnetic part relative to the metal coil, and the changes in the pressure of the gas source is accurately reflected.