Abstract: For the reservoir with subsequent water drive after polymer flooding, the key step to further producing remaining oil after polymer flooding and enhancing oil recovery is to find out the starting mode and mechanism of micro remaining oil. Based on the micro lithography simulation model, the micro flooding experiments are carried out in three ways: periodic water injection, increasing displacement pressure gradient and liquid flow steering. It is clear that the cluster and blind end remaining oil can be produced by the liquid flow steering and the increasing displacement pressure gradient, so as to improve the development effect after polymer flooding. After polymer flooding, it has been implemented in the upper layer of V oil formation and Ⅲ oil formation of Hetaoyuan formation of Paleogene in Shuanghe oilfield, which has achieved good results and provided a basis and direction for further EOR after polymer flooding.