Carbon-fiber-reinforced-polymer (CFRP) materials have been widely used in military and civilian fields to replace metals as load-bearing structural components. Nevertheless, due to the complex and anisotropic internal structures, its electromagnetic (EM) protection capability is different from metal materials. Aiming at studying the EM properties of CFRP materials, an efficient analysis method based on the anisotropic finite-difference time-domain (FDTD) algorithm was proposed. First, the equivalent EM parameter tensors of a single-layer CFRP lamina were calculated by using the <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$S$</tex-math></inline-formula> -parameter retrieval method. Then, a multilayer equivalent EM parameter model was established, and the execution equations of the anisotropic FDTD algorithm were derived. Finally, the influence of layer number, fiber orientation pattern, carbon fiber conductivity, and doping ratio on EM properties were studied by using the obtained method. The numerical analysis results indicated that the proposed method could improve the computational efficiency significantly while keeping the accuracy. The conclusions can provide certain engineering guidance for the electrical application of CFRP materials.