With regard to the fact that SF

6

gas leakage occurs occasionally in electric power industry

which threatens personal safety

electric equipment and atmospheric environment

a gas leakage accident caused by cracking of a basin insulator in GIS room is taken as an example to investigate the diffusion process and distribution law of SF

6

leakage gas in the true size GIS room based on the computational fluid dynamics model （CFDM）. It is found that during the process from the beginning of leakage to uniform distribution

the SF

6

undergoes four stages

i.e.

jetting

gravitational expansion

air entrainment

and passive diffusion. Furthermore

arecovery strategy of SF

6

leakage gas is proposed

including properly arranging SF

6

gas detection device in the horizontal plane with a height of 0.3 m to quickly and efficiently detect the leakage gas within 10 s

putting SF

6

gas recovery devices into leakage area for work within 30 s and placing them mainly to four corners of GIS

and reasonably adding recovery devices in central area of the GIS room.