Abstract: In order to study the characteristics of oil-water two-phase seepage in a reservoir at a very high water-cut stage, a water flooding experiment with a high injection multiple(200 PV) was carried out. The effects of different permeability, different injection ratio and different injection speed on oil displacement efficiency were compared and analyzed. The experimental results show that under the condition of high injection ratio, the permeability of oil phase decreases slowly, the permeability of water phase increases greatly. The water drive characteristics curve appears upturned 'inflection point'. After the inflection point,the water consumption increases sharply. The higher the permeability, the higher the oil displacement efficiency. Increasing the injection speed can improve the oil displacement efficiency. The research results provide an experimental basis for the efficient development of the reservoirs in extra high water-cut stage.