Based on the fast detection problem of aero-engine turbine Blades, a new differential eddy current sensor is developed with mechanical self-compensation, the research of automated eddy current testing experiment on turbine blade of aero-engine is developed with the five axis linkage contour automatic detection system. The results show that using the eddy current sensor with the automatic detection system is able to eliminate the lift-off signal, reduce jitter interference, and effectively improve the signal-to-noise ratio compared with manual detection. This method is expected to be applied to the metal with complex curved surface like turbine blade.