Based on the practical anti-freezing problems of indirect air-cooling system in several domestic power plants, the freezing phenomenon occurred in air-cooled radiator tube was analyzed from the aspects of equipment selection, control system and actual operation. Combined with the meteorological features in north China, northeast China and northwest China regions, some anti-freezing measures were proposed for the design and operation of SCAL indirect air-cooling system, which could provide technical supports for the application of SCAL indirect air-cooling system in north China, northeast China and northwest China regions.