Using Film Wizard™ Optical software, we obtained the optimal structural parameters of the thickness of each film layer of DLC/Ag/DLC sandwich structure through computer simulation. Then, FDLC/Ag/FDLC sandwich films with different Ag layer thicknesses were prepared by magnetron sputtering equipment. The surface of the films was dense, smooth, and had uniform particles. The luminous optical transmittance of the FDLC (30 nm)/Ag (16 nm)/FDLC (40 nm) sandwich films in the visible region reached 76.8%. When the thicknesses of the silver layer were 14, 16, and 18 nm, the Figure of Merit of the sandwich films reached 53.6 × 10−3 Ω−1, 66.3 × 10−3 Ω−1, and 52.8 × 10−3 Ω−1, respectively, and all were high values. These values were significantly better than most other previously reported ones for multilayer film electrodes. The optical band gap of the sandwich films was in the range of 1.61–2.54 eV. The band gap was regulated through the thickness of the Ag layer, and the regulation range was approximately 0.93 eV. This finding showed that the FDLC/Ag/FDLC sandwich films can potentially be applied to transparent electrodes and solar cell films.