Abstract: When the aircraft is inspected and repaired at the field, the eddy current testing sensor has the problems of poor applicability, low sensitivity and poor accessibility when inspecting the engine blade root in-situ. In order to detect the fatigue crack defect on the root of the blade, in this paper, the core detection surface of sensor is processed and a profiled eddy current detection sensor with a high degree of coincidence with the root of the blade is designed, based on the swirl ring theory and the shape characteristics of the root of the compressor blade. The experimental result shows that the newly designed profiling sensor can eliminate the lift-off effect because of the irregular shape of the blade root, and the sensor has good stability and high sensitivity.