<p>Revealing the wave velocity and resistivityl 2021characteristics of rocks under freeze–thaw cycles and their coupling mechanisms is essential for understanding the mechanical degradation behavior of rocks in seasonally frozen soils regions rocks and improving the interpretation of geophysical exploration data. In this study, Sandstone specimens subjected to different numbers of freeze–thaw cycles were measured for longitudinal wave velocity, electrical resistivity, and NMR T₂ spectra. The evolution of wave velocity, resistivity, porosity, and pore-size distribution during freeze–thaw processes were analyzed. Results show that both wave velocity and resistivity decrease with increasing freeze–thaw cycles, with their rates of change gradually diminishing, whereas porosity increases continuously with an accelerating rate. Resistivity is found to be more sensitive than wave velocity to microstructural deterioration. Combined with T₂ spectra and observed degradation features, the mechanisms of wave velocity and resistivity variations were revealed from both macroscopic and mesoscopic perspectives. Quantitative relationships among wave velocity, resistivity, porosity, and freeze–thaw cycles were established, and a wave velocity–resistivity correlation model was further developed using porosity as a bridging parameter. This model reasonably captures the coupled variation of wave velocity and resistivity during freeze–thaw processes. The findings provide theoretical support and experimental data for evaluating and predicting rock mass damage in seasonally frozen soils regions.</p>