The discharge in high-voltage electrical equipment may cause the decomposition of gas and has impact on power system security. It is necessary to test the adsorption characteristics of γ-Al

2

O

3

to the decomposition product of the new environment friendly insulating gas. Firstly

C

3

F

7

CN/N2 mixed ga

s discharge experiment was performed in the gas insulation performance test platform

and the main decomposition products such as CF

4

C

2

F

6

C

3

F

8

CF

3

CN

C

2

F

4

C

3

F-6 and C

2

F

5

CN were detected. Secondly

gas samples were collected in different environmental phases and analyzed by GC-MS before and after adsorption by γ-Al

2

O

3

. Finally

adsorbent and gas molecular models were constructed based on the density functional theory to analyze and verify the adsorption effect. It is found that γ-Al

2

O

3

can adsorb C

3

F

7

CN and its main discharge decomposition products. The adsorption effect of γ-Al

2

O

3

to C

3

F

7

CN is even stronger than its products

so it is difficult to be used as an adsorbing material for C

3

F

7

CN type gas insulated equipment. However

due to the low cost of γ-Al

2

O

3

it can be used in waste gas treatment for new environment-friendly insulating gas.