Secondary-tertiary combination was a new development concept and mode in recent years for China's high-water-cut old oilfields under the environment of medium and low oil prices, which has entered the stage of industrial application. In view of the absence of EOR evaluation theoretical model for the development characteristics of "secondary-tertiary combination", based on the comprehensive analysis of the existing EOR evaluation methods at home and abroad, proposed to construct the EOR evaluation theoretical model based on the static method. According to the development characteristics and practice of secondary-tertiary combination in domestic oilfields, seven key similarity criteria and parameters which have great influence on the recovery rate of secondary-tertiary combination were selected. Based on the action mechanism and characterization mechanism of secondary-tertiary combination, the theoretical model of secondary-tertiary combination for EOR evaluation was established to characterize reservoir properties, percolation characteristics and time-varying characteristics from the perspectives of percolation mechanics and reservoir engineering. Considering the heterogeneity of reservoir and the uneven distribution of oil, gas and water in multilayer heterogeneous developed reservoirs,introduced the whole reservoir permeability Lorentz coefficient and the whole reservoir fluidity Lorentz coefficient to modify the theoretical model of secondary-tertiary combination for EOR evaluation. Taking the actual development dynamic parameters and five-point well network of a reservoir in Dagang oilfields as an example, the calculation method of the coefficient in the theory model of secondary-tertiary combination for EOR evaluation was presented, and the enhanced oil recovery prediction curves of secondary-tertiary combination were obtained. It showed that the model had better reliability and applicability by the comparison results with numerical simulation. It provided scientific basis and technical support for the evaluation and prediction of the development effect of secondary-tertiary combination and the economic and effective development of old oilfields.