Detachable pressure gauge connector fastening device

The utility model relates to the technical field of pressure gauge installation, and discloses a detachable pressure gauge joint fastening device, which comprises a pressure gauge, a fixing ring and a needle valve, the outer side of the pressure gauge is fixedly connected with a cap, the outer side of the pressure gauge is fixedly connected with a connecting rod, the outer side of the connecting rod is provided with a first external thread, and the outer side of the connecting rod is provided with a second external thread. First internal threads are formed in the inner surface of the cap, the fixing ring and the needle valve are in threaded connection during installation, through arrangement of the limiting ring, when the fixing ring and the needle valve are connected to a certain depth through the threads, the sealing ring is installed on the inner top face of the cap at the moment, then the connecting rod and the fixing ring are in threaded connection, and after the connecting rod and the fixing ring are ro