Abstract: Underwater explosions (UNDEX) in deep-sea environments involve complex interactions between detonation products, water compressibility, and high hydrostatic pressure, making both theoretical modeling and experimental validation particularly challenging. While previous research has provided valuable insights into the basic features of shock wave propagation and bubble dynamics in underwater explosions, most existing studies are limited to shallow water scenarios or narrowly defined environmental parameters. Systematic investigations into the behavior of UNDEX under varying deep-sea conditions remain relatively scarce. This study aims to bridge that gap by conducting a comprehensive numerical analysis of shock wave load characteristics and gas bubble pulsation behaviors under a range of deep-sea conditions. A modified version of the unified bubble model, known as the Zhang equation, is employed to simulate the dynamic response of the underwater explosion across varying water depths, charge masses, and stand-off distances. The simulation framework accounts for both nonlinear pressure attenuation and the strong coupling between shock waves and bubble oscillations. The results reveal that the peak pressure of the shock wave is primarily influenced by the charge mass and stand-off distance, and increases with water depth at an approximate rate of 1% per kilometer. In contrast, both shock wave impulse and specific shock wave energy decrease with increasing water depth and stand-off distance, but show a positive correlation with charge magnitude. In terms of bubble dynamics, the maximum pulsation radius is found to be highly sensitive to both charge mass and ambient pressure, with larger charges producing more extensive pulsation cycles. Notably, as water depth increases, the suppressive effect of hydrostatic pressure becomes more pronounced, significantly weakening the intensity of bubble pulsation. Furthermore, the simulation indicates an asymmetry in the pulsation cycle: the expansion phase consistently lasts slightly longer than the collapse phase. These findings contribute to a more nuanced understanding of underwater explosion phenomena in deep-sea environments and have practical implications for naval engineering, subsea structural safety assessment, and explosive ordnance disposal in complex oceanic settings.