Abstract: In this paper,numerical simulation is done by ANSYS finite element analysis software.According to the variation of thickness of nonconductive cladding over nonmagnetic workpiece,the two-dimension model of the probe coil is built,the impedance variation of probe coil is acquired,and normalization of the impedance value of the probe coil is realized.The calculated simulative result is coincident with the traits of the real transducer.Thus,an effective analysis method and reference basis is consequently offered for the research of ECT theory,transducer design and practical application.