Abstract: Unmanned aerial vehicles(UAV) plays an important role in flood control emergency rescue due to its advantages of easy use, flexibility, high data resolution and low cost. In the flood season of 2022, the largest flood occurred in the Raoyang River in Liaoning Province since the hydrological records. At the same time, the water level of the river channel exceeded the warning for a long time, and the Shusilian section of the Raoyang River broke out. The UAV was applied to the dangerous situation of the Raoyang River breach, and the tasks of emergency survey such as river patrol and dike patrol, aerial photography, etc. were carried out. The three UAV application scenarios were described in detail, and the application suggestions of the UAV for flood emergency monitoring were put forward, providing reference for the future emergency monitoring of dangerous situations.