A novel metal-dielectric-metal structure with extraordinary optical transmission (EOT) is designed by punching the circular hole array in double-layer metal and embedding the symmetrical split ring resonators (SRR) in the circular hole. Transmission characteristics of the structure are simulated by the electromagnetic simulation software. Influences of geometrical parameters of cell structure on the transmission peaks are investigated. Results show that the number of transmission peaks can be increased effectively by increasing SRR, and the multi-frequency enhanced transmission in 0.2～1.1 THz can be realized. According to the field distribution of metal surface at transmission peaks, the transmission peaks are related to the magnetic plasmon resonance (MP), localized surface plasmon (LSP), propagating surface plasmon (PSP), Fabry-Perot resonance(F-P) and the hybrid coupling among them. Results have some guiding significance for the further study of transmission characteristics and transmission mechanism on EOT. It also provides an important reference for the design and performance analysis of terahertz microwave devices.