The invention relates to a GPRS-based urban underground integrated pipe gallery water supply pipeline online monitoring system which mainly comprises four parts: pipeline monitoring sites, a GPRS data transmission network, a central control room, and an automatic control link. Monitoring data is transmitted to the central control room through a GPRS network. Pressure, flow, liquid level and residual chlorine data of a water supply pipeline is collected and processed, and the operation state of the water supply pipeline is analyzed based on the data transmitted back wirelessly. When the data of the pipeline is abnormal, alarm is raised, and meanwhile, computer-aided control software is started automatically to close a switching valve installed at a faulty site, and the operation state of the underground integrated pipe gallery water supply pipeline is detected, diagnosed and controlled online. When the pipeline fails, the position of the faulty site is located accurately by using a GIS and a GPS, and fault information is displayed on the display screen of a monitoring center. Therefore, the damage caused by accidents is reduced, and the operation efficiency and quality of the water supply pipe are improved.