The cooling tower of a continuous hot dip galvanizing line is more than 60 meters high, with complex structure and with various equipments installed in it. The dynamic characteristics of the cooling tower have important effects on the strip vibration of the process section. In order to better reveal the effects of dynamic characteristics of the cooling tower on the strip vibration, this paper designs a model to simulate the cooling tower based on the theorem of the similarity theory. The LMS modal testing system is used to test the dynamic characteristics of the model and the prototype, and it is found that their dynamic characteristics are basically similar to each other. So a reliable tower model is obtained for a vibration testing device of the process section to investigate the strip vibration.