The invention discloses a wide-temperature nanoparticle counter. The wide-temperature nanoparticle counter comprises an air inlet shunting structure, a saturator, a condenser and an optical counter, wherein the saturator, the condenser and the optical counter are communicated in sequence, the saturator, the condenser and the optical counter are all provided with temperature control units, and a liquid working medium of which the thermal diffusion coefficient is greater than the mass diffusion coefficient is stored in the saturator. According to the invention, to-be-detected gas is divided into two paths through the air inlet shunting structure, one path is filtered, enters the saturator and carries working medium steam to enter the condenser, and the other path enters the condenser from the center of the bottom of the condenser through a capillary tube or a micropore channel and is mixed with the gas carrying the working medium steam, wherein the working medium is selected from alcohols, silicone oil, esters or a solution formed by mixing at least two of the silicone oil, the esters and the alcohols; and aiming at different to-be-detected sample gas temperatures, different liquid working media are selected, so that effective measurement of the number concentration of the nanoparticles in a wide temperature range is realized.