The natural draft cooling tower with water-cooled collectors has advantages including pump lift saving, being a type of energy-saving tower, and being suitable for application in huge capacity nuclear power plants. The height of the rain zone is reduced due to the existence of water-cooled collectors under the fill, which leads to a change of the tower's performance. In this paper, a three-dimensional mathematical model of the thermal and aerodynamic field of the tower is established. The thermal and resistance characteristics of the tower have been studied by a numerical simulation method. The study results include: (1) Owing to the existence of water-cooled collectors, the resistance of the rain zone is decreased and the total resistance of the tower is also decreased; (2) as the height of the rain zone for the natural draft cooling tower with water-cooled collectors is lower, the air velocity distribution in the fill section is more uniform than that of the natural draft cooling tower; and (3) the cooling efficiency of the tower with water-cooled collectors is superior to that of the natural draft cooling tower.