The invention discloses an equipment low-voltage fault assessment method. The method comprises: firstly, establishing a sensitive load voltage tolerance curve VTC model of the equipment according to historical operation data of the equipment for describing the working duration of the equipment under different voltages; determining a random estimation model of the probability of low-voltage faultsof the equipment in an operation uncertain area in the sensitive load voltage tolerance curve VTC model for describing the possibility of low-voltage faults of the equipment at all points in the operation uncertain area; and establishing a low-voltage fault probability evaluation model of the equipment according to the random evaluation model and the voltage reduction duration probability of the equipment corresponding to each voltage reduction moment to obtain the probability that the equipment has a low-voltage fault in the operation uncertain area, thereby realizing quantitative evaluationof the low-voltage fault condition of the equipment. The invention also provides an equipment low-voltage fault evaluation device and equipment and a storage medium, which have the above beneficial effects.