Airgel felt is a flexible thermal insulation material synthesized through a special process using silica airgel as the main material and compounded with reinforcing fibers, such as glass fiber and pre-oxidized fiber. It is soft, easy to cut, low in density, inorganic fireproof, overall hydrophobic, and environmentally friendly. It can replace traditional flexible insulation materials such as glass fiber products, asbestos insulation felts, and silicate fiber products that are not environmentally friendly and have poor thermal insulation properties. Especially in the 500℃ temperature range, the performance is excellent.