There are many kinds of insulating materials, which can be divided into gas, liquid and solid. Commonly used gas insulation materials are air, nitrogen, sulfur hexafluoride insulation PC film, etc. Liquid insulating materials are mainly mineral insulating oil, synthetic insulating oil (silicone oil, dodecyl benzene, polyisobutene, isopropyl biphenyl, aryl ethane, etc.) two types. Solid insulating materials can be divided into organic and inorganic two categories. Organic solid insulating materials include insulating paint, insulating glue, insulating paper, insulating fiber products, plastic, rubber, lacquered paint pipe and insulating impregnated fiber products, electrical film, composite products and adhesive tape, electrical laminated products, etc. Inorganic solid insulating materials mainly include mica, glass, ceramics and their products. In contrast, solid insulation materials variety, also the most important.

Different electrical equipment to insulation material performance requirements have different emphasis. High voltage electrical equipment such as high voltage motor, high voltage cable insulation materials require high breakdown strength and low dielectric loss. Low-voltage electrical equipment with mechanical strength, breaking elongation rate, heat-resistant grade as the main requirements.