Abstract: Acording to material attributes and organization characteristics of carbon fiber composite material, three-dimensional simulation of eddy current test method for measuring the coating thickness of the composite material was carried out using ANSYS software, analysed the effect of changes in the coating thickness of the coil impedance under the conditions of non-uniform conductivity. The results show that selecting detection frequency(600~700kHz),the coil impedance and coating thickness will have good linear correlation. The results of experiment and simulation calculation have good consistency.Indicates that the eddy current method to measure coating thickness special composite material has good resolution, which provides a reliable theory basis and technical support for realizing high-accuracy measurement of carbon fiber composite coating thickness using eddy current testing method.