Since the self-operated pressure regulating valve does not require other external energy sources such as power and air source, it is driven only by the energy of the medium itself, which is energy-saving, environmentally friendly and easy to use. After installation, the pressure value can be set to automatically operate. It is more and more widely used in occasions where the control accuracy is not high and the power supply and air source are lacking. But in the use process, we must pay attention to the particularity of the selection, otherwise it is easy to cause accidents. In the process of use, attention should be paid to the selection and installation environment used. Therefore, it is very important to understand the working principle and structure of the self-operated pressure regulating valve in detail.