When SF6 gas-insulated metal-enclosed switchgear（GIS）is used in alpine areas and outdoor areas withharsh environment

in order to avoid liquefaction of SF6 gas due to the influence of outdoor ambient temperature in al-pine areas

and to avoid leakage of SF6 gas caused by sudden change of outdoor harsh environment

a metal-enclosedswitchgear filled with SF6 gas is put indoors.In order to cooperate with this arrangement

a GIS outgoing line wallbushing is designed and developed.The bushing is connected with the GIS switchgear indoors

and then the bushingis connected with the outdoor equipment through the wall.Firstly

this paper introduces the design and site installa-tion scheme of wall bushing.Then

the mechanical strength stress and strain of the flange installation part of wall bush-ing are analyzed by finite element method.The analysis results show that the dangerous section and maximum stressof the flange installation part of wall bushing are located on the adjusting screw and expansion bolt

and the optimiza-tion scheme of adjusting screw and expansion bolt is given.The optimized wall bushing has been put into operation inalpine regions abroad

and has been running steadily for more than three years.