Environmentally friendly gases such as C4F7N, HFO1336mmz(Z), with low global warming potential (GWP) and high insulation strength, are expected to partially replace SF6 in high-voltage electrical equipment. This substitution is expected to drive the development of green, low-carbon, high-voltage equipment, aligning with the objectives of "Emission Peak and Carbon Neutrality". The characteristics of gas-solid interface discharge, the generation of solid deposits under abnormal conditions directly impact the operational safety of environmentally friendly insulation systems. Therefore, conducting thorough research before large-scale application is crucial. This paper reviews the current research progress on these topics, summarizing the global development and application of environmentally friendly insulation gases and related high-voltage equipment. It also analyzes the research progress on the charge accumulation at the gas-solid interface and the surface flashover characteristics. Additionally, it discusses the composition and formation process of solid deposits resulting from the deep decomposition, along with their impact on interface insulation and measures to inhibit their formation. This review provides valuable insights for the research and development of environmentally friendly gases and insulation equipment.