The pressure stability of the reverse balanced pressure reducing valve directly affects the fuel supply characteristics of the liquefied natural gas vehicle.Therefore, it is necessary to study the pressure stability of the pressure reducing valve.In order to make the test results obvious,only the valve return spring was processed by using different technics, such as pressure treatment, pressure and heat treatment, pressure and heat and low temperature treatment.After each process, the simulation test of a certain number of pressure reducing valve was carried out, and the stability of the valve outlet pressure under the repeated impact in the low temperature medium was tested.It is verified that the third treatment processes can significantly improve the stability of the outlet pressure of the pressure reducing valve, which has a certain reference value for the development and production of similar valves.