The utility model discloses a monitoring alarm device falls in grid voltage temporarily, include: data acquisition module, wireless transmission module and data processing module, data acquisition module include a plurality of data acquisition units, and the voltage signal of the await measuring node of data acquisition unit in to the electric wire netting gathers in order to generate the voltage signal data, the voltage signal data are passed through wireless transmission module and are transmitted to data processing module, data processing module handles whether take place voltage dip in order to judge to the voltage signal data of receiving, transmit the voltage signal who gathers to data processing module through wireless transmission, whether data processing module carries out the comparison with predetermined standard value after carrying out analysis processes to data, can judge voltage and take place to fall temporarily to making corresponding early warning, having realized carrying out real time monitoring to different node's in the electric wire netting voltage, when a certain node takes place the voltage dip problem, send out the function of police dispatch newspaper to the user, it can remote data transmission to have, adaptation environment advantage such as extensive.