Abstract: With the increasing of wind power generation facilities, structure safety is particularly important in the service of wind power towers. Wind power towers are a typical top-heavy structure which is similar to a kind of thin-wall cylindrical structure. The supporting structure of a wind power tower is forced under the pressure of the upper engine room, rotor and blades, the side of the tower is thrust by ocean wind, and when earthquakes happen the tower undergoes the horizontal and vertical seismic action. Since the whole structure of the tower is asymmetric, in order to clarify the mechanical characteristics and ensure the structure safety, the tower structure was studied by foreign and domestic numerical calculation methods. The differences in force of the tower structure were analyzed under wind load only, earthquake load only and the wind-earthquake load combination case. Then the dynamic responses of the tower structure were performed under the combined action of wind and earthquake load with different earthquake input directions. The results pointed out the earthquake input direction which is most disadvantageous to the tower structure and the weak position of the tower structure is door opening location under this condition.