In the process of CO₂ geological storage, the pore pressure of the formation will increase, which may induce CO₂ to flow along the bonding surface and threaten the safety of the wellbore. At present, the research on the formation pressure response in the process of CO₂ injection pays more attention to the sealing potential of the reservoir and the sealing performance of the cap rock, and the influence of reservoir pressure accumulation on the interface debonding is not considered when analyzing the risk of bonding surface channeling. Taking the Ordos onshore saline aquifer storage project as an example, combined with the actual engineering geological parameters, a dynamic response analysis model of formation pressure for CO₂ geological storage was established, and the dynamic response law of formation pressure was analyzed. On this basis, the risk analysis model of channeling at the second bonding surface was constructed. The risk coefficient of channeling was used as the basis for evaluating the risk of channeling at the second bonding surface. The sensitivity analysis of reservoir thickness, permeability and injection rate was carried out, and the main factors affecting the accumulation of formation pressure and channeling at the second bonding surface during CO₂ injection were clarified. The results show that the formation pressure at the injection point will rise rapidly at the initial stage of injection, and then decreases rapidly and then decreases slowly until the minimum maintenance pressure is reached, and the pressure decreases rapidly after the injection stops. The peak formation pressure and maintenance pressure are linearly positively correlated with the injection rate, and nonlinearly negatively correlated with the reservoir thickness and permeability. The weight of the influencing factors affecting the accumulation of formation pressure and the channeling of the second bonding surface is reservoir permeability, injection rate and reservoir thickness in turn. It is recommended that the CO₂ geological storage project should select the layer with permeability≥10 mD and thickness≥30 m when optimizing the injection target layer, and ensure that the injection rate of a single layer does not exceed 6 kg/s during the CO₂ injection process. The research can provide reference for the site selection and layer selection and injection scheme design of CO₂ geological storage project in China.