The self-operated pressure regulating valve is a valve that does not require any additional energy and can work in places where energy and gas sources cannot be provided. It integrates measurement, execution and control functions, and uses the pressure of the medium being adjusted to achieve automatic pressure adjustment product. The valve adopts fast-opening flow characteristics, which can adjust the pressure setting value freely during operation, and has the advantages of sensitive action and good sealing performance. It is suitable for the automatic control of various gas, liquid and steam media for decompression, voltage stabilization (used for post-valve adjustment) or pressure relief, holding pressure (for pre-valve adjustment). The attached condenser can be used at a temperature of ≤350 ° C. With fast opening flow characteristics, sensitive action and good sealing performance, it is widely used in various industrial equipment such as petroleum, chemical, power, metallurgy, food, light textile, machinery manufacturing and residential building groups.