Abstract: Based on elastic wave theory, the dispersion equation of ice-guided waves in sea ice under asymmetric air-ice-water coupling conditions is derived. The dispersion characteristics are solved for typical ice-acoustic parameters, and a two-dimensional finite element model is established to simulate ice-guided wave propagation. Through theoretical calculations and finite element simulations, the leakage attenuation characteristics of ice-guided waves in sea ice are investigated, and the factors influencing leakage attenuation are analyzed. The results indicate that when the phase velocity of most ice-guided waves approaches the longitudinal wavespeed, transverse wavespeed, or surface wavespeed in sea ice, the wave energy becomes more concentrated within the ice layer and at the air-ice interface, reducing energy leakage into the water and resulting in lower leakage attenuation coefficients. The bending, replacement, shifting, and separation of the real wavenumber curves for low-order ice-guided wave modes are related to leakage attenuation. Leakage attenuation causes the wave amplitude to decay exponentially with propagation distance, and only waves with negligible or zero leakage attenuation can propagate over long distances in sea ice. Additionally, the leakage attenuation coefficient at a given frequency-thickness product is inversely proportional to ice thickness. Furthermore, a larger normal displacement at the ice-water interface leads to a higher leakage attenuation coefficient for ice-guided waves.