This product is the first medical-grade home air purifier at home, designed and developed aiming at patients with respiratory tract infection and susceptible populations. By adopting medical-grade HEPA (high efficiency particulate air filters) to filtrate and purify indoor air, this product effectively filters bacteria, and can reach medical-grade purifying effect. A hierarchical arrangement is adopted for integrating complex keys, so the panel is more delicate, clear and easy to use. Light revealed from the top outlet allows users to visually observe changes to the current air quality by the light color.