Electro-osmosis can reduce the water content of silt quickly and improve its undrained shear strength. Hence, silt can be turned into resources by electro-osmosis. But the major problem to be resolved is to raise the efficiency and save energy during engineering applications. The comparative tests between natural drainage and three ways of reducing water content by electro-osmosis in silt were conducted using a newly developed apparatus.Water discharge, current and electric potential were recorded during the tests，and water content and undrained shear strength were measured at the beginning and the end of the tests. Then soil characteristics were studied from the point of energy consumption, electro-osmotic efficiency and costs on the basis of the measured data. The results show that when dealing with dredged silt by electro-osmosis, the purposes of improving efficiency and saving energy to reduce the water content are achieved by moving the electrodes parallel and searching appropriate conditions of electrodes distance and working time.