There are problems, such as thermal residual stress and second bonding layers, in radome which is prepared by metal FSSs (frequency selective surfaces). To avoid these disadvantages, carbon fiber fabric/epoxy composite which has good compatibility with radome wall structure of polymer composite was adopted to prepare FSSs; the free space method was carried out to evaluate the electromagnetic transmission characteristics of the composite FSS specimens; the numerical analysis model was employed to analyze the electromagnetic transmission mechanism and influencing factors of FSS. Results show that: the composite FSS with carbon fiber can realize the function of frequency selection, while the transmission loss at the position of resonance frequency is great; the electromagnetic transmission performance of composite FSS can be adjusted by changing the aperture-to-cell ratio, thickness, conductivity and dielectric constant. 