Our lives are becoming more and more modern, and the energy sources we use are becoming more and more diverse. Regardless of whether it is natural gas, coal gas or new energy sources, attention must be paid to prevent leakage. On the one hand, the leaked energy will pollute the environment, on the other hand, it is also a waste of scarce resources. The most important point is that the leaked energy will pose a threat to human health. Therefore, the use of pressure relief valve is very important. It can monitor the pressure in the transportation pipeline at any time to prevent hidden dangers caused by excessive internal pressure. Therefore, its working principle is also everyone should master. This article will introduce the working principle of the pressure relief valve.