Abstract: Abstract In recent years, the rapid global development of composite materials has elevated wind power to one of the foremost application domains for composite materials. Influenced by manufacturing processes and material characteristics, wind turbine blades may develop various defects during manufacturing and usage, which can lead to blade damage and affect the normal operation of the entire turbine. Therefore, conducting reliable and effective nondestructive testing (NDT) on wind turbine blades is key to ensuring operational stability, reducing maintenance costs and enhancing safety. This paper integrated the current application status of composite materials in the wind energy field, detailed various types and characteristics of common defects during blade production, processing, and operational phases. Additionally, recent advancements in NDT technologies for composite materials were surveyed, the strengths, weaknesses, and application scenarios of different NDT methods were outlined. Furthermore, a professional outlook was provided on the future development trends of nondestructive testing for composite materials used in wind turbine blades.