A dry air-water heat exchanger, wherein a cooling fan, a main tube row, at least an air pre-cooling water tube row, a water evaporator and a catchment chamber are set in a housing, wherein the air pre-cooling water tube row is provided to pre-cool for the entering air, and the water evaporator is provided to evaporate water for heat exchanging after air pre-cooling to thereby lower the temperature of the entering air, and the circulating refrigerant (or the circulating water) inside the main the row is heat exchanged by the main tube row, to thereby perform the high-efficiency cooling process with minimum energy and water consumption, to thereby cool and lower the temperature of the circulating refrigerant (or circulating water), to improve the cooling efficiency of the circulating refrigerant (or circulating water), and achieve the purpose of reducing bacterial growth and scale formation.