SF

6

gas is used widely in power industry due to its excellent performance. In case of discharge or overheating failure

SF

6

gas will inevitably decompose. The decomposition mechanism of SF

6

is studied and the decomposition feature of the SF

6

is mastered so to improve the operation and maintenance level of the equipment. In this paper

the related research progress of SF

6

gas discharge decomposition mechanism is summarized fr

om such fields as SF

6

molecular dissociation and characteristic product generation path. In view of the limitation of qualitative detection methods

it is pointed out that the research methods such as DFT

ReaxFF can clarify the complex decomposition process of SF

6

.The basic measurement and analysis methods for the research of gas decomposition characteristics

including gas chromatography mass spectrometry

infrared absorption spectroscopy and gas sensor method

are emphasized. Among them

gas sensor is the important development direction of in-built sensing and on line monitoring of SF

6

gas insulated equipment in the future due to its such advantages as smart and strong response. The process of the research of SF

6

decomposition characteristic from qualitative evaluation to quantitative analysis is introduced. The research progress on fault diagnosis of gas insulation equipment based on decomposition characteristics analysis is summarized

in which the characteristic gas concentration ratio method and the method of combination of product analysis and traditional partial discharge detection method are the most representative methods. However

these methods still need to be improved and quantitative standards need to be proposed to promote the application in the operation and maintenance of power system equipment.