The dynamic analysis has been adopted for the calculation of the low-order natural frequency and harmonic response data of the steel tower of vertical axis wind turbine, as well as the dynamic relation between the wind turbine and the tower. When the wheel rotates at 160rpm, the harmonic load has a very serious destructive damage to the tower. In order to avoid the system failure caused by the system resonance in the engineering design, some optimizations have been taken on satisfying the security and reliability of the tower. This study provides the scientific basis for the dynamic design and the optimization. The conclusion shows that the most effective method of raising the natural frequency is to reduce the weight of the structure when the material and the structural style are determined. As a result, the difference between harmonic response and resonance frequency of the structure rises to 21.3％ from 0.3％ after reducing the weight of the tower by 21.3％.