Abstract: For nondestructive inspection of T-type blade root of turbine groups, an inspection method for T-type root cracking by using phased array ultrasonic technology was proposed though analyzing the limitations of conventional ultrasonic testing as compared with the phased array ultrasonic theory. Following that, a special miniature linear phased array probe was customized and practical application for one of thermal power plants in Xinjiang was realized. Combined with magnetic particle and radiographic inspection methods for secondary verification, the practicality, feasibility and accuracy of T-type turbine blade root inspection by using phased array ultrasonic technology were proven.