Abstract: Compressed air energy storage（CAES） is a kind of clean energy storage technology. The integration of CAES into the power system provides a new solution for achieving accommodation of high proportion of renewable energy, and it has an impact on the reliability evaluation of the power generation and transmission system. First, the Markov method is used to establish a general failure probability model for CAES, and the model can consider the damage of air storage container. Secondly, a system index that can reflect the energy leakage on the energy storage side is proposed for this model, and the impacts of different control parameters of CAES on the indices of the power generation and transmission system are discussed. Then, the sensitivity analysis method is used to identify its key components, which affects the indices of the combination module, device of CAES and power generation and transmission system in the modified IEEE RTS-79 system. And it can be combined with the classical dichotomy theory to quantify the capacity credit of CAES integration. Finally, the influence of wind farm and CAES coordination on the system reliability is discussed. The evaluation results can provide useful reference for the design and configuration scheme of CAES.