The full-process guarantee technology for indoor air quality in buildings is based on the entire life cycle of design, construction, acceptance, and operation and maintenance of the building, and a comprehensive guarantee technology for indoor air quality is proposed. This technology mainly includes decoration pollution control technology and particulate matter prevention and control technology. In terms of decoration pollution control technology, by establishing testing and evaluation methods and developing testing equipment, a VOCs source evaluation technical system and standard system with "release rate" as a parameter have been formed. In terms of particulate matter prevention and control technology, the design process, calculation model and design parameter set for indoor particulate matter prevention and control in buildings are proposed; ventilation and purification system selection methods for different outdoor atmospheric particulate matter pollution zones are established; temperature and pollutant concentration are independently controlled. The low-running resistance ventilation and air conditioning purification system solves the problem that temperature, pollutant concentration and energy consumption cannot be taken into account in traditional systems; An air quality monitoring platform has been built to monitor indoor air quality levels in real time and automatically control the fresh air system. Indoor air quality indicators: Through the application of full-process protection technology for indoor air quality in buildings, the indoor particulate matter level of the project is less than 35μg/m3, and the concentration levels of formaldehyde and TVOC are higher than those of the "Standard for Indoor Environmental Pollution Control of Civil Construction Engineering" GB50325 -2010. 50% increase. Performance indicators of low-operating resistance ventilation and air-conditioning purification system with independently controlled temperature and pollutant concentration: The indoor particulate matter concentration level is less than 35μg/m3, which saves more than 50% energy compared with a purification system with the same purification effect. The developed low-operating resistance ventilation and air-conditioning purification system with independently controlled temperature and pollutant concentration can not only ensure that the indoor PM2.5 concentration is less than 35μg/m3, but also saves more than 50% energy compared with a purification system with the same purification effect. Through the application of full-process protection technology for indoor air quality in buildings, the indoor particulate matter level of the project is less than 35μg/m3, and the concentration level of formaldehyde and TVOC is 50% higher than that of the "Standard for Indoor Environmental Pollution Control of Civil Construction Engineering" GB50325 - 2010.