Due to the complex compound interfaces and electric field stress concentration

GIS cable termination is the position with high fault rates in high voltage cable line. At present

the frequency bands of sensors for various partial discharge detection technologies are different

application scope and anti-interference performances are different

and these lead to the detection rate of GIS cable termination defect is relatively low which goes against the comprehensive diagnosis in field application. In this paper

detection principles of ultrahigh frequency（UHF）

high frequency（HF）and ultrasonic partial discharge（PD）detection technologies and the adaptation of these technologies to GIS cable termination were discussed

and a combined diagnosis scheme was given which suited the termination well in field application. Then an abnormal discharge defect of a GIS termination of 110 kV cable line in Sichuan Province had been tracked and monitored for nearly one year

and combined diagnosis was carried out with the given scheme. HF partial discharge detection was used to determine the defection type and identify the defection phase.Considering no abnormal discharge signal was detected through ultrasonic detection

UHF partial discharge technology was used to locate and analyze the discharge defect. Finally

the accuracy and validity of location analysis for PD source were verified through the dissection analysis which provided a typical case for the defection diagnosis of GIS cabletermination

and this supported condition maintenance of cable termination strongly.