Abstract：Chongqing is located in the eastern region of Sichuan Basin. Carbonate rocks are widely distributed, especially in southeastern and northeastern Chongqing, where karst is developed and dissolution phenomena are diverse, impacting regional flood protection standards. Taking the formulation of flood control project plan of Ping'an Township in Fengjie County as an example, according to the hydrogeological conditions of karst area, a new plan is put forward after comparing various schemes. The new plan proposes implementation of flood protection by means of a combination of ground and underground, to realize flood discharge in flood season and utilization of karst groundwater resources in dry season. It provides reference for the final determination of the scheme.