A metamaterial microstructure based on a single cross resonator and a four-ring resonator is designed in this paper. The EIT-like effect and slow-light effect of metamaterial microstructure are studied. By optimizing microstructure parameters, the maximum transmittance of 96.35% and the maximum group refractive index of 228.38 are obtained. A layer of tungsten disulfide (WS2) thin film is embedded between the metamaterial microstructure layer and SiO2 substrate. When the carrier concentration of WS2 increases from 1.4x1017cm-3 to 1.4x1021cm-3, the permeability decreases from 94.18% to 29.31%，the group refractive index decreases from 226.85 to 136.33. In addition, when the surface of the microstructure is covered with 5?m thick analyte whose refractive index is from 1.0 to 2.0, the resonant peak sensitivity of the microstructure is 135.39GHz/RIU. When the carrier concentration of WS2 is 1.4x1020cm-3 , the resonant peak sensitivity of the microstructure is 40.00GHz/RIU. This research is expected to provide novel research ideas for the design of high sensitivity refractive index sensor and all-optical tunable THz slow optical device