Abstract: Ground penetrating radar is easy to operate with fast detection speed, high accuracy, and reliable results, making it an effective means of detecting hidden dangers in embankments. This article introduces the application of ground penetrating radar in the detection of hidden dangers in the main stream embankment of Liangshui River in Beijing. It mainly detects whether there are caves, cracks, loose bodies, high sand layers, gravel layers, and leaks in the embankment, and identifies the basic situation of the location, direction, size, and burial depth of the abnormalities, so as to take effective measures to eliminate the safety hazards of the embankment and ensure its safe operation.