Abstract:  To address the problem that the heat transfer efficiency of the system is limited due to the mismatch of the heat capacity of the three fluids in the air-flue gas total heat transfer process, a counter-flow evaporative condensing total heat exchanger suitable for flue gas waste heat recovery is proposed. A water film with a very low flow rate is used instead of the intermediate fluid to remove its limitation on the heat transfer efficiency. A two-dimensional model of the heat exchanger is established and its heat and moisture transfer process is numerically simulated. The effects of Gas flow patterns,flue gas inlet flow rate, spray water mass flow rate, heat exchanger plate aspect ratio and channel spacing on the performance of the total heat exchanger are investigated. The results show that when the flow of gas is from above into below and air from below into above the flue gas, inlet flow rate is 2.5～3.5 m/s, the heat exchanger plate aspect ratio is 3～5 and the channel spacing is 5～7 mm, the heat transfer performance of the full heat exchanger is better. Under the condition that the air remains saturated, the smaller the spray water mass flow rate is, the better the performance of the full heat exchanger is.