Abstract: During high temperature period in summer, the temperature of condensate water in direct air-cooling unit may be over the inherit range of ion exchange resin, which are strong base anion exchange resin and filter element. The systemic study of heat resistance on condensate polishing treatment with anion exchange resin and filter element of powder resin filter at high temperature in the air-cooling unit was implemented. Six representative kinds of anion exchange resin were selected to implement the static experiments at 95℃. Three selected anion exchange resins, which meet the standard of electric power industry DL/T953-2005, were implemented dynamic experiments for heat-resistant at 70 ℃, 75 ℃ and 80 ℃.Through testing the change of the rate of decline in anion exchange resin alkali groups and the extraction of the three anion exchange resins in the high temperature cycle, the thermal stability performance of anion exchange resin was inspected. The anion exchange resin with finer heat-resistant performance applied in power plant for determining the effect of silicon removal was selected. The organic extraction of winding filter element of powder resin filter at high temperature was tested. The result shows：（1） the exchange capacity of strong base groups of anion exchange resins is inversely proportional to run time and operation temperature at 70 ℃, 75 ℃ and 80 ℃.The longer the operation time, the higher the operation temperature, the faster the exchange capacity of strong base groups decreased. Comparing the three selected kinds of anion resin, the heat-resistant performance of big hole of Ⅰtype styrene of anion exchange resin of Germany is better; （2） the heat resistance of polypropylene winding from different manufacturers varies greatly. The heat resistance of the two selected kinds of winding filter element in air-cooling unit can meet the technical requirements, but the operation temperature should not be more than 80 ℃.

Key words: air-cooling unit, condensate polishing treatment, anion exchange resin, heat resistance, filtering element