DC GIS/GIL insulation systems endure long-term exposure to unipolar electric fields and temperature gradients. Under the combined influence of electric and thermal fields

charge migration and accumulation occur

leading to localized electric field distortion and potentially inducing surface flashover. This threatens the reliability of equipment insulation. During switching operations

polarity reversals

and load changes

the insulation system experiences dynamically coupled fields of DC

transient

and temperature gradients. This causes non-uniform variations in the mesoscopic and microscopic parameters of insulating materials

significantly complicating the charge accumulation process at gas-solid interfaces and severely impacting long-term equipment performance. We review the significant research achievements in the mechanisms and control methods of charge accumulation at gas-solid interfaces in insulators by domestic and international scholars. We first summarize the influencing factors of charge accumulation at gas-solid interfaces in DC GIS/GIL insulators from the perspectives of electric and thermal fields

and then organize research findings on the dominant mechanisms of charge accumulation at gas-solid interfaces. Second

we summarize the impact of gas-solid interface charge accumulation on surface flashover. Finally

we outline the future research challenges in developing interface charge inversion algorithms and studying accumulation processes under dynamic electrothermal coupling conditions during operational scenarios.