Abstract: As an essential technology for maintaining the stable operation of spacecraft propulsion systems, the management of liquid propellants in storage tanks holds significant practical importance. Therefore, research on fluid management devices—such as slosh baffles—is of great relevance. This study conducts detailed numerical simulations and experimental investigations on the effects of different baffle configurations on liquid sloshing characteristics in partially filled storage tanks under terrestrial gravity. Numerical simulations were performed on the sloshing processes of tanks equipped with various baffle structures. The frequency and damping ratio of the liquid sloshing, extracted from the simulation data, were used to characterize the oscillation response of the liquid to external excitations. The results indicate that, compared with the original configuration (Configuration 1), Configuration 2 (baffles with near-wall blades) reduces the oscillation amplitude of the liquid mass center and increases the damping ratio. Configuration 4 (double-sided perforated baffles) halves the liquid oscillation decay time and significantly enhances the damping ratio. In contrast, Configuration 3 (single-sided perforated baffle) deteriorates the damping performance. Sloshing experiments further verify the reliability of the numerically obtained damping ratios.