Abstract: A method for monitoring and safety evaluation of a dam body defect of a check dam is provided, including steps of: obtaining multi-source remote sensing data, unmanned aerial vehicle (UAV) data, ground monitoring data and sensing images through a three-dimensional data network; identifying the sensing images through an R-CNN algorithm and a Fast R-CNN based on the UAV data and check dam body database to determine check dams having defects and types of defects, defect data and position data; performing classification statistics of the check dams having defects according to the types of defects; building a three-dimensional model of the dam body safety evaluation standards for check dams after classification according to the position data and the ground monitoring data; input the defect data in a check dam safety performance evaluation module to obtain simulation data; and completing the evaluation according to the simulation data and the three-dimensional model.