Online nondestructive sampling device for detecting sulfur hexafluoride decomposition gas

The utility model provides an online nondestructive sampling device for detecting sulfur hexafluoride decomposition gas. The device comprises a pressure reducing and stabilizing valve, a first control valve, a multi-way part, a second control valve, a vacuum pump and a check valve which are sequentially connected through pipelines; the pressure reducing and stabilizing valve and the check valve can be respectively connected with a gas inlet/ outlet detecting opening of a gas chamber to be detected, of an electrical device so as to form a closed circuit. The device further comprises at least one detecting unit which is connected to the multi-way part; the detecting unit is the detecting device for detecting gas in the SF6 decomposed product online. With the adoption of the device, the gas can be sampled and recovered, the electrical device can be really continuously monitored online, and moreover, the gas loss or pollution can be avoided.