The invention provides a drainage pipe network monitoring system. The drainage pipe network monitoring system is constructed in the aspects of water level, water quantity, water quality, gas, mud deposition depth, pipeline structure safety, well lid displacement, video monitoring and the like. The drainage pipe network monitoring system comprises water level, flow and water quality monitoring points arranged at key nodes of a sewage pipe network, a rainwater pipe network and a combined pipe network, mud deposition depth monitoring points arranged at key nodes of a pipeline network with low gradient, low flow speed and the like, gas monitoring points arranged at the sewage pipe network and a septic tank where people are dense and poisonous, harmful, flammable and explosive gas is prone to being gathered, pipeline structure safety monitoring points arranged at the positions with structural safety risks such as road surface settlement and landslide, well lid displacement monitoring pointsarranged in important areas such as crowded areas and areas prone to overflowing, and video monitoring points arranged at the positions prone to waterlogging such as lower through channels, tunnels and sunken squares. The drainage pipe network monitoring system achieves system monitoring of a drainage pipe network.