The key to enhancing oil recovery of very high water cut oilfield lies in analyzing oil displacement efficiency in different position of reservoir, which mainly focus on the analysis of dimensionless cumulative flowing into water volume and oil displacement efficiency distribution. In order to get the oil displacement efficiency distribution characteristics to future analyze influence on oil displacement efficiency by changing well pattern, oil displacement efficiency in different position of homogeneous reservoir is studied by combining the analysis of core displacement experiment with oilfield practice in this paper. Firstly, streamline function and streamline distribution between injection-production well in homogeneous reservoir is researched by the potential function and potential distribution with the five-point well pattern. Secondly, the method of flow distribution on the streamline between the injection-production well is studied according to change law of seepage resistance. Thirdly, dimensionless cumulative flowing into water volume along the streamline is calculated based on the core size to analyze its distribution characteristics about homogeneous reservoir and obtain dimensionless cumulative flowing into water volume at different position of the reservoir matching the core displacement experiment. Finally, the distribution characteristics of oil displacement efficiency are got by statistical analysis for the change of oil displacement efficiency as the dimensionless cumulative flowing into water volume in real oilfield. This study may provide technical measure with oilfield enterprise to enhance the oil recovery of very high water cut oilfield.