The present invention disclose a thermal power plant combined ventilation direct air cooling system, including hyperbolic air cooling tower, a plurality of air intake channels arranged along the circumferential direction on outboard of the air cooling tower bottom, and the air intake channel is cylandrical structure of open outer end and inner end communicated with the air cooling tower internal, inside each air intake channel is arranged with air condensator unit connected with steam turbine exhaust pipe and condensation water collecting pipe, outside air exchange heat with the air condensator unit in the air intake channel and expel from the air cooling tower. The invention sets air intake channel and the matching hyperbolic air cooling tower, and makes full use of pumping action of the air cooling tower to airflow in the premise of assuring fan activity, greatly reduce the affect if ambient wind velocity, wind direction, temperature and assure reliable and stable cooling to the heat dissipating finned tube, and provide guarantee to power generating plant stable power generation. The invention provides a feasible, optimized technology approach for present thermal power plant alteration.