Double-medium testing device for performing gas pressure test and hydraulic test on natural gas pressure vessel

A double-medium testing device for performing a gas pressure test and a hydraulic test on a natural gas pressure vessel comprises a liquid nitrogen tank, a water tank, a first low temperature stop valve, a second low temperature stop valve, a third low temperature stop valve, a first manual ball valve, a first electromagnetic ball valve, a cryogenic pump, a first safety valve group, a second manual ball valve, a third manual ball valve, a second electromagnetic ball valve, a check valve, a fourth manual ball valve, a first pressure transmitter, a first pressure gauge component, a fifth manual ball valve, a gasifier, a sixth manual ball valve, a second safety valve group, a second pressure gauge component, a seventh manual ball valve, a third electromagnetic ball valve, an eighth manual ball valve, a second pressure transmitter, a third pressure gauge component, a ninth manual ball valve, a fourth electromagnetic ball valve, a silencer, a third safety valve group, a tenth manual ball valve, an automatic control system and a fifth electromagnetic ball valve. The device can realize free switching between two media, can adopt nitrogen as a gas source to carry out a gas pressure test, can use water to carry out a hydraulic test, and is simple and convenient to operate.