In response to industry challenges such as low sensitivity, limited detection area, and poor linearity in conventional methods for measuring ice thickness on aircraft surfaces, this study proposes a sensor array based on the nested split-ring resonator (NSRR) structure. This structure is characterized by strong radiation capability, low loss, high quality factor, strong field confinement effect, and ease of miniaturization. A sensor array composed of 72 nested split-ring resonator (NSRR) units (11×11 mm) was designed and fabricated, achieving a compact footprint of 88×99 mm. This system quantifies ice thickness by monitoring shifts in resonance frequency. ADS equivalent circuit simulations revealed a deterministic relationship between the NSRR’s equivalent capacitance and the array’s resonance frequency. HFSS electromagnetic simulations further demonstrated the array’s capability to detect media with varying dielectric constants and measure ice thickness at millimeter-scale resolution, with a simulated sensitivity of 23.46 MHz/mm. Experimental results further validate a strong linear relationship between the resonance frequency and average ice thickness, with a coefficient of determination (R2) of 0.989. The maximum detection sensitivity reaches 21.15 MHz/mm, with a maximum relative error of less than 5%. These findings demonstrate that the proposed sensor facilitates large-area, quantitative detection of average ice thickness on structural surfaces, offering advantages such as high sensitivity, extensive coverage, low cost, and scalability.