Abstract: Considering the existence of metal electrode corrosion and low efficiency in the late period of the conventional electro-osmosis in combination with the vacuum preloading method, the drainage effects of the electro-osmosis method, vacuum preloading method, vacuum preloading method in combination with electro-osmosis and cathode straight drainage method are investigated by using the self-developed device. By monitoring the drainage amounts, electricities, pH, settlements and strengths, the treatment effects of the above methods are compared. The results between the two kinds of vacuum preloading methods in combination with electro-osmosis are also compared. It is shown that: (1) The drainage amount of soil treatment using the vacuum preloading method in combination with electro-osmosis is the largest, and the strength and settlement are both larger than those of other methods; (2) The drainage amount of the cathode straight drainage method is larger than that of the vacuum preloading method in combination with electro-osmosis in the initial eight hours, the pH value is more stable, and the surface of soil is more uniform. Furthermore, the inhibition between the vacuum preloading and the electro-osmosis can be improved by using the cathode straight drainage method. Therefore, a new research idea is proposed for the enlargement of application range for the electro-osmosis in combination with the vacuum preloading method, that is, the cathode straight drainage method and the electro-osmosis in combination with the vacuum preloading method can be combined for soil treatment.