Abstract: Most existing studies of ice breaking by high-pressure airgun bubbles focus on homogeneous freshwater ice and cannot fully represent the heterogeneous structure of saline ice, so this study aims to clarify the failure mechanism produced by the coupling between multistage bubble loading and the material properties of saline ice. An integrated experimental framework linking material properties, load evolution, and damage response was established. First, uniaxial compression and three-point bending tests were conducted to characterize the mechanical response of saline ice over a range of temperatures, salinities and strain rates. The results reveal a pronounced ductile-to-brittle transition under uniaxial compression, whereas the bending strength increases monotonically with decreasing strain rate, and this asymmetry between tensile and compressive responses governs the dominant failure mode of the ice plate. Next, bubble loads were calibrated beneath a rigid boundary, and ice-breaking tests were performed under different combinations of salinity, ice thickness, standoff distance, and initial airgun pressure. A synchronized dual-view high-speed imaging system and wall-pressure measurements were used to record bubble evolution, pressure histories, and crack propagation. The loading process was identified as four successive stages, including the initial shock wave, gas-jet loading, secondary pulsation, and water-jet impact, which allowed each load stage to be directly related to the corresponding crack response. The dimensionless standoff parameter H and thickness parameter T were then introduced, and the results of 73 tests were classified to construct failure-mode maps for different salinity levels. The results show that brine pockets and brine channels markedly reduce the tensile and flexural resistance of saline ice, which makes bending-induced tensile failure the dominant failure mode. Ice damage develops progressively through initial crack initiation, radial through-thickness cracking, and the subsequent formation of circumferential cracks. As the standoff distance increases, the initial shock attenuates rapidly, whereas bubble migration toward the boundary sustains the later loads; however, these later loads act as concentrated point loads whose effective area contracts more rapidly with distance, so that only radial cracks form at large standoff distances. Increasing salinity shifts the compound-failure region toward larger T values, thereby extending the effective operating window of high-pressure airgun-assisted ice breaking.