Due to a series of advantages of GIS

it is widely used in various voltage levels. In this paper

the simulative calculation and graphic analysis of the test waveforms obtained from the GIS field impulse insulation test is conducted firstly

which illustrates that the impulse test waveform is closely related to the GIS pipe-bus bar length.The test area should be simulated before field impulse test and the appropriate impulse test wave type is selected according to the results of simulation calculation. Secondly

the ferromagnetic resonance phenomena of electromagnetic voltage transformer（PT）are analyzed in site charging test. It is considered that the breaker’s inter electrode capacitance

too short bus connection to PT and the phase angle when the circuit breaker cutting off the PT are the main reason that cause PT core magnetic saturation and result in PT ferro-resonance. Thirdly

the different action times of the three-phase lightning arrester（LA）at the same position in GIS operation are analyzed. It is considered that the main reason is due to the phase angle difference 120° in three phase power system

which results in that the three phase switching overvoltage peaks are different at the breaker switching instant. And the impulse currents of three phase LAs installed in the same place are different. Finally

the stream shape creepage trace occurred on the insulator surface are explained. It is considered that arises from the breaker’s inter electrode capacitance and/or induction of adjacent transmission lines to no-load lines and results in the induced current flowing continuously on the insulator surface corroded by the arc decomposition

such current value is not high but the duration is longer. Through these problems research in GIS site acceptance and operation

it may provide theoretical basis with reference value and practical evidence for the safe operation of GIS.