The mathematical model of enthalpy recovery wheel was built and verified by comparison with existing literatures, based on which, the effects of air velocity, proportion of fresh air and exhaust air, fresh air temperature (when humidity ratio is constant or relative humidity is constant), fresh air humidity ratio on the heat recovery efficiency of enthalpy recovery wheel were investigated. The results show that the sensible heat efficiency, latent heat efficiency and total heat efficiency of enthalpy recovery wheel decrease with increasing of air velocity; when proportion of fresh air and exhaust air increases, or fresh air temperature increases (relative humidity is constant), and the sensible heat efficiency, latent heat efficiency and total heat efficiency increase, too; with increasing of fresh air temperature (humidity ratio is constant ), the sensible heat efficiency increases, while the latent heat efficiency and total heat efficiency decrease; when fresh air humidity ratio increases, the sensible heat efficiency remains constant, while the latent heat efficiency and total heat efficiency increase.