At present

the replacement of pure SF

6

with SF

6

/N

2

gas mixture in power industry has been promoted

and the development of

detection of discharge decomposition products of SF

6

/N

2

gas mixture is of great significance to the assessment of the operation status of electrical equipment. For exploring the law of the discharge decomposition products of SF

6

/N

2

gas mixture

the arcing discharge experiment is performed

and the technical problem of difficult rapid and effective detection of trace components is solved by copper tube bleed air technology in combination with gas chromatograph

and the qualitative and quantitative detection of SF

6

/N

2

gas mixture is achieved. The reaction heat of the main decomposition path is calculated by using the density functional theory to analyze the formation reasons and volume fraction changes of the decomposition products. The results show that the decomposed components of SF

6

/N

2

gas mixture under arcing discharge mainly include CF

4

CH

4

CO

2

C

2

F

6

SO

2

F

2

SOF

2

SO

2

NF

3

and N

2

O

among which

the amount of generation of SOF

2

SO

2

is the highest

followed by NF

3

and N

2

O

and that of CF

4

and C

2

F

6

is the lowest. And the greater the proportion of N

2

in the mixed gas

the higher the production of NF

3

and N

2

O after arcing discharge

and the lower the production of the remaining components. The two components of NF

3

and N

2

O are stable and non-toxic

and can be used as the characteristic components of the decomposition products of SF

6

/N

2

mixed gas.