Post-tensioned bonded prestressed concrete towers have gained wide recognition and application in the wind power industry because of their excellent integrity and high load-bearing capacity. During the design process, crack verification under normal service conditions is often a controlling factor in structure design, and this verification is closely related to the calculation of prestress losses. This paper, which combines Chinese and European codes, introduces in detail the calculation method for prestress loss in internally post-tensioned structures. Additionally, the differences in the calculation methods specified in the Chinese and European codes are compared and, considering the characteristics of wind turbine towers, methods and recommendations for selecting relevant parameters are provided, with the aim of serving as a reference for the design of similar structures.