The optical and electrical properties of transparent conductive multi-layer films with dielectric/metal/dielectric structures are superior to those of single-layer transparent conductive oxide films or metal films, and the multi-layer films can be prepared at low temperature. The transparent conductive multi-layer ZnO/Ag/SiN film is prepared by magnetron sputtering at room temperature, and then the film is measured by variable-angle spectral ellipsometry. The refractive index and the extinction coefficient of every single layer are obtained by building physical models and fitting. The multi-layer model is established based on the single-layer models, and the measured and fitted ellipsometric spectra of multi-layers fit well. The results show that the carrier concentration in the Drude model of the functional Ag layer barely changes while mobility of the Ag layer varies under different flow rate ratios of O2 to Ar in reactive ZnO deposition. The mobility of the Ag layer becomes upmost when the flow rate ratio of O2 to Ar makes ZnO corresponding to the oxidization state. At this point, it is revealed by X-ray diffraction that the Ag layer has the best crystallization and preferred orientation.