This paper introduced the design principle and development process of the intelligent air purifier of medical level. The air purifier adopts the modes of filtration, activated carbon adsorption, and plasma-combined purification. The highly-efficient filter screen and activated the carbon filter layer can filter dust particles, adsorb formaldehyde, toluene and other harmful gases. The antiseptic plasma purifier can release purification factor and can cause active sedimentation of pm10 and pm2.5 particles, purify the harmful gas such as formaldehyde and toluene, and kill pathogenic microorganisms. Intelligent control system can adjust air volume of the running fan automatically according to the change of air quality and thus can effectively save the energy consumption. It is suitable for purification and disinfection of indoor air in the medical environment.