Abstract: The operating principle of pressure regulator is introduced. The pressure regula tor, used in natural gasproduction, purification and transmission and distribution, doesn't work well in pressure regulating. So, some improvements are made on the material of valve body and purification of gas, that is, to change the stainless steel body to Co+Cr alloy body to increase the hardness and toughness, install filter to decrease dust and impurities of gas and increase the exhaust for the separator. For its a pplication, the type selection of pressure regulator is carried out.