Years of development practice have witnessed the maturity of research on the mechanism of enhanced oil recovery（EOR）with CO2 flooding in low permeability reservoirs in China. However，the theoretical research on reservoir engineering was not sufficient and the theoretical model for the recovery evaluation of CO2 flooding in low permeability reservoirs was not available. Based on the EOR mechanism of CO2 flooding in low permeability reservoirs，the basic similarity criteria and key parameters for the theoretical research on the recovery evaluation of CO2 flooding were selected with the generalized reservoir engineering method. The main-factor characterization functions were created to characterize the development characteristics and EOR mechanism of CO2 flooding in low permeability reservoirs. A theoretical model for the recovery evaluation of CO2 flooding in low permeability reservoirs was construced. According to the actual development parameters of CO2 flooding in representative low permeability reservoirs in China，the coefficients of the model were solved by the single-factor virtual development method of numerical simulation. The applicability of the theoretical model was analyzed by the multi-factor virtual development method of numerical simulation. The reliability of the theoretical model was verified by comparing the actual recovery with the calculated result by the theoretical model. The results show that the proposed model is applicable and reliable and provides theoretical basis and technical support for quantitatively evaluating CO2 flooding development and improving the evaluation method of CO2 flooding in low permeability reservoirs and the theoretical research on reservoir engineering.