The transmission and magneto-optical Faraday rotation effect are studied in a sandwiched structure containing the magneto-optical metal Co6Ag94 by tunneling mechanism. The double transmission peaks and single transmission peak are discussed in the sandwiched structure, respectively. The results show that the transmission and magneto-optical Faraday rotation effect of both double transmission peaks and single transmission peak in the sandwiched can simultaneously be enhanced due to the slow wave effect of the localized electromagnetic fields at the interface between the magneto-optical metal layer and the magnetophotonic crystals. In addition, Faraday rotation angle -45° is given in our sandwiched when the magneto-optical metal Co6Ag94 is gained. This property provides a theoretical basis for the design of compact magneto-optical isolation devices.