In order to review the research progress in the electrical properties of environment-friendly insulating gases in recent years

and to advance the research and application of new gases

we have refined two ways to assess gas insulation performance and the suitable conditions from three aspects of discharge mechanism

discharge characteristics

and new gas research

namely critical reduced field strength and breakdown field strength. The influences of local uneven electric field

pressure

temperature

and gas mixture on electrical properties are obtained

which is helpful for evaluating the electrical properties of new gas. To solve the problem of poor efficiency of new gas research

the theory of performance prediction based on microscopic parameters of gas molecules are introduced. Finally

two directions are put forward in the research of environment-friendly gas. One is to optimize the insulation performance considering the coupling influence factors in the practical equipment. The second is toexplore new gases with better electrical properties based on the theory of molecular structure parameters prediction.