A new characteristics matrix method along with the formulas based on conductivity, which can be used to calculate the optical properties of an ultra-thin conductive composite multilayer dielectric structure, is derived for the first time as faras we know based on the electromagnetic boundary conditions Maxwell's equations required. It can be used to calculate the reflection, transmission, and absorption of light, provided that the conductivity of the conductive body is known, also it can overcom the shortcoming of the traditional transfer matrix method, i.e.it is necessary to know the permittivity and permeability of the material. By using the proposed method, the optical behavior of graphene and composite multilayer structures can be obtained in the THz frequency range.