Abstract:Finding out the actual operation of underground sewage pipeline is an important basis for later maintenance. However, the current detection method cannot fully grasp the accurate detection of underground pipelines. Aiming at the operation of Zhengzhou subway crossing beneath the sewage pipeline, the sewage pipeline is indirectly and intuitively detected by using the high-density electrical method and ground penetrating radar detection method, and combined with the self-developed detection technology of color imaging system floating on the water surface. The problems of leakage, cavity and dislocation of the sewage pipeline are found, and the multi-dimensional and three-dimensional monitoring of the pipeline is realized, which provides the technical support for the protection, repair and reinforcement of the underground pipeline.