According to the laminated structure and the electrical anisotropy of carbon fiber reinforced polymer (CFRP) composite, an finite element method based on the A-Φ(magnetic vector potential-electrical scalar potential) is proposed to effectively deal with the calculation of eddy currents in CFRP. The numerical method is implemented with COMSOL multiphysics software and the simulation model of anisotropic CFRP laminate is established. The distribution of eddy current density in the plane and thickness directions, and the eddy current distortion caused by the crack defects in the composites are obtained through simulation. Furthermore, the influence of the fiber orientation, crack defect and exciting current frequency on the amplitude and phase of eddy current coil impedance is analyzed based on the impedance method, which is verified by experiment tests. It can be seen from the results that the larger crack defect and the higher frequency lead to the larger coil impedance change and the better detection efficiency. Meanwhile, it can be also seen that the detection effect of orthogonally composite laminate is significantly better than unidirectional composite plate.