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CO2 geological storage is an effective means to reduce CO2 emission into the atmosphere and alleviate the dangers of greenhouse effect. The sloping strata are common in nature due to tectonic and diagenetic effects, which have practical significance to study the effect of sloping strata on CO2 storage amount and security. Based on a demonstration project in Fukang sag of Junggar Basin, Xinjiang, the influence of the variation of stratigraphic dip angle of CO2 reservoirs with mid-high permeability on the process of CO2 geological storage was studied by means of numerical simulation. The results show that the injection of CO2 leads to a significant increase in the stratigraphic pressure near the well; compared with horizontal strata, the sloping strata have a significant difference on pressure distribution, CO2 migration distance, CO2 injection rate and storage amount. CO2 lateral migration distance of sloping strata is significantly larger than that of horizontal strata under the action of asymmetric stratigraphic pressure. The pressure distribution and dissipation process in sloping strata are quite different from that in horizontal strata; as a result, the influence of sloping strata on CO2 total injection amount presents a non-monotonic change.At the initial stage of injection, the CO2 total injection amount in sloping strata is less than that in horizontal strata, and with the injection time extension, the CO2 total injection amount in sloping strata gradually approaches and exceeds that in horizontal strata. After injection for 20 years, the larger the dip angle of sloping strata is, the more helpful to the increase of CO2 total injection amount, which is contrary to the conclusion of sloping strata with low permeability by previous studies. The existence of stratigraphic dip angles can promote CO2 migration to the shallow part, the larger dip angle can greatly increase the risk of CO2 leakage to the shallow aquifer or atmosphere. Therefore, the influence of sloping strata on the storage efficiency and security should be fully considered in the site selection of CO2 geological storage. [ABSTRACT FROM AUTHOR]