We propose a novel combination of a radiation field model and the transfer matrix method (TMM) to demonstrate plasmon-induced transparency (PIT) in bright-dark mode waveguide structures. This radiation field model is more effective and convenient for describing direct coupling in bright-dark mode resonators, and is promoted to describe transmission spectra and scattering parameters quantitatively in infinite element structures by combining it with the TMM. We verify the correctness of this novel combined method through numerical simulation of the metal-dielectric-metal (MDM) waveguide side-coupled with typical bright-dark mode, H-shaped resonators; the large group index can be achieved in these periodic H-shaped resonators. These results may provide a guideline for the control of light in highly integrated optical circuits.