In the longdistance refined oil transportation pipeline, the sudden closing of the valve or the power failure of the system may cause the oil flow velocity reduced sharply, the inertial effect of the oil and the compressible nature of the oil may cause the pressure to rise sharply in the pipeline. The sudden changed pressure can cause vibration, noise and even damage to the oil pipeline. In order to prevent the occurrence of this phenomenon, surge relief valves are usually installed in the piping system. Through the surge relief valve, the highpressure oil in the pipeline system can be unloaded in time, so as to reduce the oil pressure in the system and ensure the normal operation of the pipeline system. The working principle and structural characteristics of main valve and pilot valve of domestic mainstream surge relief valves were analyzed, and their structural characteristics and application occasions were expounded.