The increasing demand for ultra-precision components with complex surface geometries has stimulated the development of advanced deterministic polishing technologies. This investigation explores the impact of external vibration on the rheological properties of polishing slurry and the material removal performance during the vibration-assisted force rheological polishing (VFRP) process. The mechanical response of the vibrating workpiece surface under various vibration conditions was numerically analyzed using ANSYS Fluent 14.5. The results demonstrated a strong correlation between the surface pressure imposed on the workpiece and the applied vibration amplitude as well as vibration frequency. Experimental results validate that the introduction of vibration promotes a reversible rheological transition of the slurry from a fluid-predominant state to a solid-resembling structure, which facilitates abrasive particle confinement and subsequently enhances polishing capability. The reliance of stainless-steel sheet polishing performance on vibration parameters was evaluated. With the optimized combination of polishing speed (40 rpm), vibration frequency (80 Hz), and amplitude (0.35 mm), the 30 min polishing process yielded a material removal rate of 68.1 nm/min and reduced the average surface roughness (S_a) from 80 nm to 7.1 nm. The acquired results provide constructive direction for optimizing the VFRP process and promoting its application in high-efficiency, ultra-precision surface polishing.