Pressure relief device of pressure vessel

The utility model provides a pressure relief device of a pressure vessel, which comprises a pressure vessel body, and the top of the pressure vessel body is respectively communicated with a pressure relief mechanism and a discharge mechanism; the pressure relief mechanism comprises a pressure relief pipeline communicating with one side of the top of the pressure container body, an air outlet of the pressure relief pipeline communicates with a pressure relief cover, a partition plate is fixedly installed in the pressure relief cover, a discharge hole is formed in the top of the partition plate, an adjusting cover is fixedly installed at the top of the pressure relief cover, and an electric telescopic rod is fixedly installed on the inner side wall of the adjusting cover. The pressure vessel has the beneficial effects that materials when the pressure in the pressure vessel body is too high can be discharged through the arranged pressure relief cover and the adjusting cover, then the discharged materials are pre