The invention relates to a centrifugal water pump system monitoring device based on vacuum pump water diversion. The centrifugal water pump system monitoring device comprises a vacuum water diversion system, a water diversion state detecting device, a main circuit and a control circuit; the vacuum water diversion system and the water diversion state detecting device comprise three inlets, an outlet and three water slag separators which are connected with a centrifugal water pump, a vacuum pump/solenoid valve pipeline, a vacuum pipeline and a probe; and according to the control circuit, acquisition of the vacuum water diversion state, a voltage signal, a current signal and a switching value input signal is realized, calculation of the electric energy quality parameter, logic judgment, breakdown diagnosis and switching value outputting are realized, and the human-machine interaction function with a touch screen and the communication function of an upper computer are realized. The centrifugal water pump system monitoring device based on vacuum pump water diversion has the beneficial effects that accuracy and reliability of the water diversion detecting state are guaranteed; water slag separation in the water diversion process is realized, and the problem of damaging to the probe and a vacuum system by slag is effectively avoided; and the water-slag separator has the self-cleaning function and the all-aspect breakdown diagnosing function, so that safe and reliable operation of the centrifugal pump are effectively protected.