Flow pulsation significantly impacts pump performance. In the context of offshore equipment employing four-quadrant pumps, enhancing the precompression chamber emerges as a viable approach to mitigate flow pulsation. This study focuses on proposing methods to ameliorate the precompression chamber of a commonly used 9-plunger 40mL/r displacement pump in engineering applications. Using the AMESim simulation software, we constructed a comprehensive simulation model of the 9-plunger pump integrated with a precompression chamber, elucidating the structural mechanisms governing the precompression chamber. Building upon this foundation, we introduce the novel double damping hole channel precompression chamber structure. Subsequently, an associated AMESim model is established to investigate the impact of various parameters within this improved chamber structure on suppressing flow pulsation in four-quadrant pumps. Our findings indicate that an optimal configuration for reducing flow pulsation involves a 500mL volume for the improved precompression chamber, with damping hole C1 set at 3mm and damping hole C2 at 2mm.Further, we conducted a simulation analysis encompassing the overall speed, swash plate speed, and flow rate of the four-quadrant pump. This investigation culminated in an exploration of key parameters—including overall speed, swash plate inclination, plunger inclination, and oil characteristics—aimed at discerning their influence on flow pulsation in the modified precompressed volumetric four-quadrant pump. Notably, our results highlight that gas content characteristics within the oil wield significant influence over the flow pulsation of the four-quadrant pump. In comparison to the traditional four-quadrant pump, our proposed improved pre-compressed volumetric four-quadrant pump demonstrates superior efficacy in mitigating flow pulsation.