The continuous increase in the single-unit capacity of wind turbines and the continuous increase in the hub height have led to new requirements for the structural performance of wind turbine towers. Precast pre-stressed concrete towers that are widely used in the field for large turbines and high towers are gradually replacing traditional steel towers on the market. However, research on structural joints, especially vertical joints where several precast concrete pieces are assembled into a ring segment, is limited. One way to improve the integrity of the structure and clarify the load path is to apply circumferential prestressing to the annular precast tower containing vertical structural joints. With the structural design example in a certain concrete wind tower project, this paper analyzes the effects of different magnitudes of circumferential prestressing on the structural performance under the service loads and the ultimate loads and proposes a method to determine the optimized design of the structure.