Abstract: Aimed at the properties of fast increase in composite water cut and low level of recovery efficiency during the water-flooding treatment of conventional heavy oil reservoirs in Binnan, Bin 31-11 well cluster has been chosen as the experimental plot and a WD system has been experimentally studied in this cluster. Performance evaluation and displacement plan has been studied systematically. Experimental data including the solubility, compatibility, absorbance and the influence of chemicals on the dehydration effect have demonstrated that the WD system can effectively reduce crude oil viscosity, improve oil flooding efficiency, water flooding effectiveness and the recovery ratio of conventional heavy oil.