Oil reservoir has become an important way for CO₂ storage, while the injection of CO₂ to reservoir can also improve the oil recovery. According to Yanchang oilfield reservoir characteristics, an evaluation model for CO₂ storage was established using the formation storage, bound storage, dissolved storage and mineralization mechanism. The model was established under the consideration of CO₂ dissolution in the oil, CO₂ dissolution in formation water and free gas storage. The model was used to evaluate the CO₂ storage potential for Yanchang oilfield. The results show that the model can predict reservoir storage capacity, and the reservoir CO₂ storage stock is about 209.879×104 t. The reservoir shows very good storage potential, which can provide important basis for CO₂ displacement of Yanchang oilfield.