Abstract: With the development of power grid, its structure is becoming more complicated. The potential operation risk level of power grid is growing with the increase of uncertain factors in power grid. This paper applied risk evaluation in power grid planning, and considered the internal and external uncertainty factors impacting the development of power grid, such as national economic development, the optimal allocation of resources, and the running environment of power grid, which could make power grid planning more economic, reasonable and stronger adaptability. The challenges including large-scale renewable energy integration, the change of power grid structure, the development of modern distribution network, etc., were analyzed at first. The research progress and work of risk evaluation applied in power grid planning at home and abroad were then studied. On this basis, the risk evaluation framework for flexibility power grid planning was proposed, which consisted of evaluation objects, evaluation hierarchy and constraint factors；the overall outline and flowchart of risk evaluation were presented；the future application prospect of risk evaluation technology in the field of power grid planning in China was discussed at last.

Key words: power grid planning, risk evaluation, flexibility, uncertainty