The east Sha 20 reservoir in fault block of Shanian oilfield is one of the typical narrow strip reservoirs with edge water. The overall reservoir is of high water cut at 2012, and also flooded seriously in the well area, so it is difficult to maintain a stable production in addition to the complex remaining oil distribution. By means of comprehensive evaluation method of multiple factors and the capacitance model principle, we can identify block water flooding channel, and study the sand body on fluid channeling and the direction of it. Results show that the causes of water drive advantage channel include not only the continuous injection of injection wells of edge,but also the long-term water invasion of edge water, therefore, the effective water injection strategy research will be based on the advantage of water drive channel identification results. Combined with the planar characteristics of the reservoir and vertical remaining oil distribution, it is suitable to block layers, fill holes, infill and transfer oil wells on reservoir, and then adjust the injection-production system in different fluid channeling regions. By adjusting the water injection mode, the recovery of optimal plan can increase by 2.71% for 15 years, and the initial water cut decreases by 25%, so we can enhance and improve water flooding development of the narrow strip of reservoir, therefore providing experience for similar oilfield exploitation and later adjustment.