The invention discloses a multifunctional biological air cleaner, which comprises the following parts: a casing, an ion generator, an aerosol generator, a cleaning filter bank and an air cleaning fan, wherein the two ends of the casing are separately equipped with the indoor air inlet and the outlet of the cleaned air, the ion generator and the aerosol generator are arranged near the indoor air inlet in the casing, the air cleaning fan is arranged at the finite distant of the cleaned air outlet underside, the fan inlet is connected with the outlet of the cleaning filter bank, the casing is also equipped with a fresh air fan, a fresh air filter bank and a sleeping system comprised by the induced pipe. The invention enhances the air cleaning effect, which achieves the coexistence of the people and the device, the cleaning and sterilizing on the internet, the high volume fresh air and the self-sterilizing function.