We propose a hybrid structure of a nano-cube array coupled with multilayer full-dielectric thin films for refractive index sensing.In this structure,discrete states generated by two-dimensional grating and continuous states generated by a photonic crystal were coupled at a specific wavelength to form two Fano resonances.The transmission spectra and electric field distributions of the structure were obtained via the finite-difference time-domain method.We obtained the optimal structural parameters after optimizing the geometrical parameters.Under the optimal parameters,the figure of merit (FOM)values of the two Fano resonances reached 1.7 × 104 and 3.9 × 103,respectively.These results indicate that the proposed structure can achieve high FOM refractive index sensing,thus offering extensive application prospects in the biological and chemical fields.