Abstract: In the background of green energy transformation, the regional integrated energy system（RIES） with the new power system as the core, has gradually deepened its multi-energy coupling degree. In the process of long-term planning operation, in addition to the inherent conventional expected fluctuation characteristic of the source load itself, RIES is also easy to be affected by external disturbances, resulting in unexpected uncertainties. Therefore, this paper proposes a multi-stage rolling stochastic expansion planning of RIES considering both expected and unexpected uncertainties. First, aiming at the long-term planning of RIES and the expected uncertainty of conventional multi-energy source-load, the multi-stage stochastic planning model of RIES is established based on the information gap decision theory, considering the investment cost, energy station income and carbon tax during the construction process. Then, considering the unexpected uncertainty in the planning process, a multi-stage rolling stochastic planning of RIES is established using model predictive control theory for reference. Finally, taking the JSYZ-66-bus test system in Jiangsu, China as an example, the effectiveness of the proposed method in long-term planning is verified against conventional source-load expected uncertainties and unexpected uncertainties in the planning process, and the influence of the choice of planning direction under the risk speculation and risk avoidance strategies on the planning results is analyzed.