Abstract: With the developments of Bohai Oilfield, many oilfields have entered a high water-cut period. Stabilizing oil production and controlling water cut under the condition that the platform processing flow has reached the limit has become an urgent problem to be solved in Bohai Oilfield. It is proposed to use the underground oil-water separation technology to separate the formation production fluid directly into the well for oil-water separation. In order to better apply this technology to the site, research work on oilwater separation characteristics in the Bohai Oilfield was carried out for this purpose. In this paper, a high-speed centrifuge was used to conduct oil-water separation experiments on high-water-based production fluids in the QK17-2, CB, JZ9-3 and SZ36-1 oil fields. The research results that the extension of the centrifugation time and the increase of the centrifuge speed have no obvious promotion effect on the oil-water separation results, and the addition of demulsifier can significantly improve the oil-water separation results. The separation water flooding experiment shows that adding an appropriate amount of demulsifier is beneficial to reduce reservoir damage. Through experimental simulation, a set of rules for oil-water separation characteristics of high-water-containing production fluids with different oil properties in Bohai Oilfield was summarized, which has guiding significance for the successful application of oil-water separation technology in Bohai Oilfield.