CO₂ storage in the brine layers is one of the common countermeasures to alleviate the greenhouse effect，and dissolved CO₂ storage is a relatively stable storage mode in the process of storage，so it is urgent to find a method to accurately calculate the potential of dissolved CO₂ storage. In this paper，the CO₂ dissolution coefficient in water is calculated by using the prediction model proposed by Duan et al.，and then the theoretical dissolved CO₂ storage is obtained. Then，the index of the effective CO₂ storage coefficient is established，and the main controlling factors of dissolved CO₂ storage are considered.According to the numerical simulation and regression analysis，the prediction model of the effective storage coefficient of dissolved CO₂ storage is established. The results show that when the horizontal permeability and the formation dip angle are constant，the effective storage coefficient of dissolved CO₂ storage increases with the increase in initial pressure. When the initial pressure is constant，the effective storage coefficient of dissolved CO₂ storage increases with the increase in horizontal permeability and decreases with the increase in formation dip angle. The predicted results of the prediction model are in good agreement with the results of the numerical simulation. According to the actual parameters of Block7 in Gudong Oilfield，the theoretical storage is 65.382 Mt，the effective storage coefficient of dissolved CO₂ storage is 0.079，and the effective storage of dissolved CO₂ storage is 5.178 Mt.