Geological CO₂ storage has been thought of as an important technical means for alleviating the greenhouse effect，and the leakage risk assessment of the storage system is the basis of safe storage. In this study，the influencing factors in the leakage of the geological CO₂ storage system were comprehensively analyzed. It is believed that the leakage risk is mainly induced by the alternating stress on the wellbore and caprock produced by cryogenic fluids of CO₂ and the integrity failure of the wellbore and caprock caused by the comprehensive action of CO₂-water and rock corrosion reactions. Hence，the multi-factor influence on the leakage of the geological CO₂ storage system was taken into account. Then，the fuzzy comprehensive evaluation（FCE）theory was used to construct a model for the hierarchical relationships between factors leading to CO₂ leakage risks，and the model was employed to assess the leakage risks of the geological CO₂ storage system. Specifically，the nonlinear normal membership function was applied to construct the membership matrix of the influencing factors with regard to comments. The analytic hierarchy process（AHP）was used to construct the comparison matrices between the influencing factors to obtain the weight subset of these influencing factors. In addition，a geological CO₂ storage system was taken as an example for leakage risk assessment. It is concluded that the wellbore for geological CO₂ storage faces a low risk of leakage while the cap rock and the storage system have a moderate leakage risk. Moreover，the leakage risk of the geological CO₂ storage system can be dynamically tracked upon the collection of the changes of influencing factors in the process of CO₂ storage for the update of the fuzzy calculation model.