Abstract: Tertiary infill development is going to be carried out in domestic oilfields to bring into production of the non-producing reserves after primary and secondary well pattern thickening. The distribution of the remaining oil reserves after secondary well pattern thickening determines the nonhomogeneity of the tertiary thickened well pattern and the tertiary infill development has no independence in respect of series of strata. Tertiary oil recovery technolo-gies have made a large progress in China and their prospect of application is bright Quite some oil layers are left intact after polymer flooding, thus need to be further developed. This paper analyzes the deficiencies of tertiary infill development and tertiary oil recovery when they are separately applied, and introduces the possible methods to combine them together, which are simulated through numerical simulation. It is confirmed that combining the tertiary infill development with the tertiary oil recovery is feasible, and it is more favorable for enhancing oil recovery factor and improving development effects.