Doors and windows are divided into enclosure components or partition components according to their different positions, and have different design requirements to have insulation, heat insulation, sound insulation, waterproofing, fire prevention and other functions. The new requirements are energy-saving, and the heat lost by door and window gaps in cold regions accounts for about 25% of the total heating consumption. The requirement for the airtightness of doors and windows is an important aspect of energy-saving design. Doors and windows are important components of the building envelope system.