The analysis and prediction of containment prestress is one of the important contents of Time Aging Analysis (TLAA) for Operating License Renewal (OLE) demonstration. Aiming to evaluate the structural integrity of containment considering the time-dependent prestress, firstly, the time-dependent prestress prediction approach based on the monitoring value of concrete strain is established, which could accurately predict the time-dependent prestress of containment within 60 years of service. According to the strain–time histories of the prestressed reinforcements, it was found that the prestress value is still above the design Minimum Require Value (MRV) when the containment operation after 60 years. Subsequently, a refined three-dimensional finite element model was established to predict the structural responses of containment under practical working scenarios. Based on the strain data of CTT test, the material parameters of concrete and prestressed reinforcement were determined by sensitivity analysis. Finally, the structural responses of containment in various service times and corresponding time-dependent prestress load were analyzed by numerical simulation. The results show that the structure integrity of containment can still be maintained under LOCA conditions within 60 years.