It is of great significance to formulate corresponding potential tapping strategies on the basis of the study of the remaining oil production law to improve the development effect of high water cut oilfields. In this paper, based on the one-dimensional core displacement model experiment, the oil content of different pore throat radius was analyzed, and the pore throat radius with higher residual oil content in the target block was determined. Based on the flow equation, considering the main force under the microscopic reservoir conditions, the retention mechanism and production limit of crude oil are studied. The results show that with the increase of the displacement time, the water phase in the large pore throat becomes the continuous phase, and the residual oil in the small pore throat forms "water injection flow around"; with the increase of the radius of the small pore throat, the critical displacement pressure gradient decreases. The potential pore throat radius of the target block is 35μm, and the corresponding critical displacement pressure gradient is 0.06MPa/m. The displacement pressure gradient during the remaining potential tapping in the high water cut period should be higher than the critical displacement pressure gradient. The above results were applied to SZ and QHD oilfields for development and adjustment in high water cut period. The well pattern was adjusted from directional wells inverse nine-point injection and production to horizontal wells combined with directional wells for row-column pattern and five-point well patterns, and the recovery rate was increased by 14.1% and 15.2%, respectively. The development effect of high water cut period was Greatly improved.