The invention belongs to the urban waterlogging early warning system technical field and relates to a road waterlogging monitoring system. The road waterlogging monitoring system comprises a three-dimensional camera, a rainwater sensor, a controller, a central processing unit and a monitoring display unit; the three-dimensional camera measures the coordinate values of a surface ground/water surface that the three-dimensional camera can cover; the rainwater sensor detects whether it rains; the controller controls the three-dimensional camera and makes the three-dimensional camera turned on when the rainwater sensor senses raining; the coordinate values measured by the three-dimensional camera are transmitted to the central processing unit through a GPRS communication module; when no water is accumulated on the ground surface, the coordinates of the ground surface are (X,Y,Z0); when water is accumulated on the ground surface, the central processing unit compares the Z value of real-time water surface coordinates with the Z0, so that waterlogging depth deltaZ can be calculated according to an expression that deltaZ=Z-Z0; when deltaZ exceeds a threshold value t, the central processing unit sends alarm signals; and the monitoring display unit displays the position of the three-dimensional camera distributed on a road through a GIS map and displays waterlogging depth in real time. The system of the invention has the advantages of accurate monitoring data and little possibility of being subject to environmental influences.