Based on the transmission characteristics of the surface plasmonic polaritons in sub-wavelength structures, a metal-insulator-metal (MIM) waveguide coupled dual T-shaped cavity with metallic baffle structure is proposed . Under the action of near-field coupling, the narrow discrete state formed by a single T-shaped cavity and the wide continuous state formed by a single baffle form the asymmetric double Fano formant through complex interference cancellation. Based on the coupled mode theory, the mechanism of Fano resonance of a MIM waveguide coupled single T-shaped cavity with single baffle structure is studied, and the structure is simulated by the finite element analysis. On this basis, the formation process of quadruple Fano resonance with double T-shaped cavity structure is studied, and the influence of upper and lower T-shaped cavity structure parameters on Fano formant is analyzed. The results show that the Fano formans generated by the upper and lower T-shaped cavities do not affect each other, and two Fano formans can be tuned independently by a single T-shaped cavity, so the MIM waveguide coupled double T-shaped cavity structure containing metal baffle can achieve four Fano formans that can be tuned independently. This structure can provide an effective theoretical reference for the design of differential sensor and wavelength division multiplexer.