Nowadays

gas-insulated transmission line (GIL) is playing an increasingly important role in the field of power transmission. It combines the advantages of cable and overhead transmission line

featuring with superior transmission performance and great potential application value. However

due to its own structural instability and other characteristics

it is easy to produce a series of faults

which seriously affects its transmission performance and safety performance. Therefore

this paper reviews some common monitoring methods for GIL. Firstly

it introduces the structure of GIL as well as its own characteristics and advantages

and then

according to the category of faults monitored in the monitoring process

the monitoring methods of GIL are divided into three major categories

which are the monitoring methods for partial discharge faults

structural defects faults

and overheating faults

and each category of methods is outlined and analyzed. Meanwhile

the specific application environment and implementation methods are analyzed. Each type of method is outlined and analyzed

and its specific application environment and implementation method are analysed. Secondly

the technical challenges faced by the monitoring of the transmission system of GIL are discussed. Finally

the potential future development trend of the proposed method is outlooked.