Fano resonance, originating from destructive and constructive interference between discrete states and a continuum, exhibits unique asymmetric line shapes, ultra-narrow spectral linewidths, and high sensitivity to the refractive index of the surrounding medium, thus showing great potential in high-performance sensors and optical switches. However, achieving selectivity tuning of multiple Fano resonances in a single device remains a key challenge in this field. Here, we propose an asymmetric multi-cavity coupled metal-insulator-metal (MIM) waveguide structure composed of a bus waveguide coupled with a square ring resonator (SRR), a semi-ring resonator (SSR), and a split semi-ring resonator (SSSR). The transmission characteristics of the structure are systematically investigated using the finite-element method. Five Fano resonance peaks are excited in the mid-infrared region (1000–3500 nm) via near-field coupling interference between the discrete states supported by the individual resonators and the continuum provided by the bus waveguide. And relying on the main control parameters corresponding to each structure, selective regulation of multiple resonance modes has been achieved. Among them, the tuning of FR2 by the SSSR radius shows a non-monotonic behavior of first blue shift and then red shift, revealing the competition mechanism between the variation of inter-cavity coupling strength and the intrinsic frequency of the cavity. In sensing applications, the structure achieves a maximum refractive index sensitivity of 3277.474 nm/RIU, a FOM of 135.23 RIU^-1 and a Q value of 143.25, which is competitive among reported MIM waveguide structures with multiple Fano resonances. Moreover, exploiting the differential responses of distinct resonance peaks to refractive index variations in different cavities, simultaneous detection of glucose and glycerol solutions is demonstrated in a single device, with concentration sensitivities of 0.39 nm·L/g and 0.37 nm·L/g, respectively. This multi-cavity coupled MIM waveguide structure utilizes the resonance regulation characteristics of multiple Fano to provide a theoretical reference for subsequent high-performance, multi-parameter, and multi-functional integrated sensing experimental research.