Owing to the low-loss characteristics of the all-dielectric materials, this paper proposes a metasurface with a silicon gap disk structure as a platform for microfluidic sensing and detection. The structure can be directly excited by incident light to produce a broad-spectrum electric dipole bright mode in a symmetrical state. When a rectangular nano-notch is introduced into the structure, the dark mode is excited, resulting in the formation of two new Fano resonances. The hybrid resonance is produced by the coupling of the electric quadrupole mode and electric dipole, as well as the magnetic Fano resonance is dominated by the magnetic dipole. The transmission spectrum characteristics are examined using the 3D FDTD method, and the influence of various structural parameters is investigated. It is observed that the structure can simultaneously achieve independent and nonindependent parameter tunings. Furthermore, the effect of the analytes with varying thicknesses in the microfluidic device on sensing performance is investigated. By selecting the optimized structural parameters, the sensor has a maximum sensitivity of 400.36 nm/RIU and a maximum Q value of 1252.3. The proposed structure provides a theoretical reference for the design of biosensor detection devices.