Abstract: Aiming at the fatigue cracks generated on the power turbine rotor blades of a certain small aero-engine, the eddy current testing method was used for in-situ inspection. However, the existing eddy current testing probes could not meet the requirements for in-situ inspection of power turbine rotor blades in terms of structure and performance. Therefore, a specialized eddy current probe was developed. Through in-factory tests and field in-situ inspection applications, the detection reliability and effectiveness of the developed specialized eddy current probe were verified. Test results showed that the proposed detection method and developed probe successfully detected artificial notches in the in-factory tests and could detect real fatigue cracks in field applications, which were consistent with metallographic examination results, basically meeting the in-situ inspection needs of power turbine rotor blades.