The invention belongs to the technical field of energy utilization and engineering thermophysics, and in particular relates to a combined dry-wet cooling tower adopting natural ventilation and combined operation mode and its application. The dry-wet combined cooling tower includes a tower body, a supporting structure, a dry cooling section, a wet cooling section and a flow distribution system; the tower body is in the form of a hyperbola, supported on the ground by a supporting structure; the dry cooling section and the wet cooling section are vertically Integrated in the same cooling tower; the dry-cooling section is located above the wet-cooling section; the dry-cooling section includes cooling triangles and dry-cooling section louvers; the wet-cooling section includes water eliminators, water distribution systems, filling areas, sumps and wet-cooling section louvers The flow distribution system includes the total inlet and outlet pipelines, the inlet and outlet pipelines of the dry cooling section, the inlet and outlet pipelines of the wet cooling section, valves and circulating pumps. The invention does not require fan power consumption, has high cooling efficiency, can provide lower water temperature out of the tower, and saves water resources.