Abstract: Taking the large SCAL indirect air-cooled tower in a 600 MW unit as an object of study, a mathematical model was established for dynamic characteristics of the tower, which was solved using Euler algorithm, so as to analyze the dynamic response of enthalpy-temperature channel to the disturbance of following factors, such as the inlet water temperature and flow rate of circulating water, the environmental temperature and the wind speed, etc. The calculated dynamic characteristics were compared with actual operation data. Results show that the dynamic characteristics obtained with above model agree well with actual measurements, with an error less than 3%, which therefore may serve as a reference for operation control of indirect air-cooling systems.