Eddy current testing is an efficient method to measure nonferromagnetic metal coating thickness and conductivity, but is often affected by lift-off and coil parameters. In this study, a new apparent eddy current conductivity (AECC) curve acquisition method is proposed, which eliminates the influence of lift-off and coil parameters, and the coating thickness and conductivity can be directly detected by extracting characteristics of the AECC. First, the impedance of a coil on a single-layer plate varying with lift-off is analyzed to establish the lift-off direction on impedance plane, and the influence of lift-off and coil parameters can be eliminated by projecting the impedance values onto the lift-off vertical direction. Second, an AECC acquisition method is proposed by rotating the impedance plane coordinate system into lift-off direction coordinate system and establishing the equivalent relationship between single-layer and double-layer metal plates based on the projection point of the coil impedance in the lift-off vertical direction. Third, two characteristics of AECC are extracted to detect the coating parameters, where the high-frequency stable value is extracted to directly obtain the coating conductivity, and the peak frequency is extracted and combined with the power function fitting method to obtain the coating thickness. Finally, the proposed method was employed to experimentally measure the coating parameters of a high-conductivity (Cu-Al) and a low-conductivity (Ti-Ti6Al4V) double-layer plates. The results show that the relative errors of the thicknesses for both metal plates are, respectively, 1.5% and 1.56%, and the relative errors of the conductivities are, respectively, 0.06% and 3.3%.