The utility model provides an automatic rinse -system of city underground drainage pipe network, including simulation pipeline, gate mechanism and switch board, the export of simulation pipeline is connected with the water pipe net, be equipped with level sensor in the simulation pipeline, gate mechanism includes frame, gate and actuating mechanism, the frame is fixed on the simulation pipeline, actuating mechanism one end is connected through first revolute pair and frame, the actuating mechanism other end passes through the second revolute pair and is connected with the gate, the gate is opened or is closed through rotating around the second revolute pair the intercommunication of export of simulation pipeline and pipeline, be equipped with the sealing washer on the gate, PLC is equipped with in the switch board, PLC and actuating mechanism and level sensor are connected. Actuating mechanism includes hydro -cylinder and hydraulic pump, the hydro -cylinder passes through oil pipe and oil pump connection. The utility model discloses can mechanical scrubbing, efficient and energy saving reduces the consumption, and simple structure easily maintains, and the security performance is high.