Abstract: Severe practical problems including visual pollution, waste of water and heat caused by the white smoke produced by wet desulphurization of coal-fired power plants have remained to be a problem. Hence, it has guiding reference for effectively controlling the white smoke and popularizing the technology of smoke elimination. In this investigation, taking the white smoke pollution caused by wet desulfurization as the research object, the white smoke reduction heat exchange system is analyzed. Special attention is paid to the influence of different operation conditions on the temperature and absolute humidity reduction of the heat exchange system and heat recovery of cooling water. Based on the cooling dehumidification and mixing white smoke process, the heat exchange system is experimentally studied in winter environment. According to results, when the air-water heat exchanger and supply air induced draft fan are running (case 3) at the same time, the temperature changes of exhaust air and supply air are the most significant. The outlet temperature and absolute humidity of the mixing zone decrease by about 74.1℃ and 0.0879kg/kg, respectively. Based on above results, it is confirmed that the mechanism of white smoke is consistent with working conditions. The generation of white smoke gradually decreases with decreasing temperature and absolute humidity under different working conditions.