Abstract: With the acceleration of industrialization iiiand the development of cities, the output of sludge is increasing. Sludge is a soft soil composed of a large amount of fine-grained soil and water. How to drain and its drainage behavior are topics worth studying. Taking commercial washed kaolin as the research object, a total of 5 groups of comparative experiments were designed to explore the problem of sludge drainage behavior when the electroosmosis method and the conventional drainage method (only mechanical pressure) were combined under constant current conditions, and the conventional drainage method test was set as a control test. The results of range analysis, variance and standard deviation analysis and coefficient of variation analysis of the final moisture content of the experimental index filter cake showed that the discreteness of each group of experiments was low, and the experimental results of this study had a strong credibility. The threshold point of the power-on time was determined according to the filtration constant of the control test, and the electroosmosis drainage test of kaolin sludge was carried out using homemade equipment, and the change law of voltage, drainage rate, drainage volume and energy consumption over time was obtained. The test results show that compared with the conventional drainage method, the combined use of the conventional drainage method and the electroosmosis method can enhance the drainage effect, and the total drainage rate is increased by 9.1%, 9.6%, 13.3%, 17.5% and 8.3% respectively; the closer the start time of power-on is to the time threshold point, the better the drainage effect; the appropriate increase in current density can enhance the drainage effect; when the power is turned on at the time threshold point, when each group of experiments reaches the same drainage volume, the current density of 2.98 mA/cm2 will save more energy in the electroosmosis drainage process.