Abstract: When fluorescent magnetic particle testing is performed on 17-4PH martensitic precipitation-hardened stainless steel axles, there is a regional linear magnetic trace display due to the presence of banded ferrite. In this paper, eddy current testing technology was used to study the first part of the wheel shaft with magnetic marks by electron microscope scanning and analyze its metal structure properties. Secondly, according to the characteristics of the axle, the coil structure and the detection effect of the eddy current probe were analyzed. Then ANSYS simulation technology was used to calculate the influence of probe coil parameters on detection sensitivity and detection depth. The relationship curve between excitation frequency and detection signal amplitude was studied. Finally, a four-channel eddy current detection probe was designed and manufactured, and the eddy current detection process of wheel shaft was developed and experimental verification was carried out. The experimental results showed that eddy current detection technology could overcome the interference caused by the band ferrite on the surface of the wheel shaft and realize the effective detection of manual grooving.