Abstract: Based on the heat and mass exchange theory between flue gas and water,by solving the basic equation of heat and mass exchange,this paper obtains the analytical solution suitable for the contact condensation heat exchange of wet flue gas,and analyzes the influencing factors of heat and mass exchange performance in the contact condensation heat exchange of wet flue gas.The results show that the water-gas ratio,droplet size and heat exchange height have great influence on the heat transfer efficiency,while the flue gas velocity,flue gas inlet temperature and spray water inlet temperature have relatively little influence.