Abstract: With the increasing production of sludge (soft soil composed of a large amount of fine particle-water complex), it is worth studying what kind of dewatering method to choose and clarify its dewatering behavior. To enhance sludge dewatering efficiency, taking commercially purified kaolin as the research material, this study systematically investigated the synergistic effects of electroosmosis-conventional mechanical combined method (using only mechanical pressure) under constant current conditions through five comparative experiments. The conventional dewatering method experiment served as the control. Results demonstrated that the combined approach significantly improved the dewatering performance, achieving 8.3%-17.5% higher total dewatering rates compared to standalone mechanical dewatering. The closer the power-on start time was to the time threshold point (50 min) of the filtration-compression stage, the higher the dewatering efficiency. A current density of 2.98 mA/cm² resulted in the minimum specific energy consumption of 1.45×10⁻³ kW·h/mL of drained water. Variability analysis revealed coefficients of variation below 0.025 across all experimental groups, confirming result reliability. The innovative adoption of graphite electrodes with a dual-side dewatering design effectively reduced the total dewatering duration to 180 minutes while preventing electrode corrosion. This research provides a theoretical foundation for optimizing the electroosmotic-mechanical combined dewatering process, which has both high efficiency and energy-saving potential.