To provide a surface treating method of a moist surface heat exchanger for improving wettability, particularly, to provide a technology for epochally improving wettability of a moist surface by deforming a heat exchanger surface such as a cooling tower, an evaporating condenser and a cooler into a hydrophilic porous structure.

This surface treating method of the moist surface heat exchanger is characterized by coating the heat exchanger surface with the hydrophilic porous structure by passing through a curing process after applying a mixture made by mixing a fine solid particle with a hydrophilic binder to the surface by a spray and dipping method. Thus, this invention can substantially and epochally improve the wettability of the surface by possessing evaporated water in the porous structure by improving expandability of the evaporated water by capillary attraction force in the porous structure.