The invention relates to the technical field of dewatering treatment of shield tunnel engineering, in particular to an automatic monitoring system used for dewatering of a shield originating well. Thesystem is arranged at the bottom of a well casing of a dewatering tube well through a static water device, and a waterproof pressure gauge is arranged at the bottom of the static water device; when awater pump starts to pump water, data detected by the waterproof pressure gauge is transmitted to a data acquisition and transmission module through a cable, the acquisition and transmission module converts signals and transmits the signals to a calculation and analysis module to determine whether an alternating current contactor needs to be closed or not so as to control whether the water pump runs or not, and then the automatic dewatering monitoring effect is achieved; the static water device is used for making the water, which is around the waterproof pressure gauge at the bottom of the well casing of the dewatering tube well, keep close to a static water state so as to achieve the purpose of accurate measurement results.