The invention provides a power switch device fault state judging method based on multi-source information, which comprises the following steps of: acquiring the state of the power switch device, the state of a switch relay protection signal and the analog value of the power switch device; carrying out a plurality of logical state combinations on the state of the power switch equipment, the state of the switch relay protection signal and the analog value of the power switch device; searching a preset fault factor value corresponding to each logic state combination in a preset logic state combination-fault factor table; substituting the plurality of logic state combinations and the preset fault factor values thereof into a preset fault judgment formula to obtain a total fault weighting value; comparing the total fault weighting value with a preset fault threshold upper limit and a preset fault threshold lower limit, if the total fault weighting value is larger than the preset fault threshold upper limit, judging that the power switching device has a fault, and if the total fault weighting value is larger than the preset fault threshold lower limit and smaller than the preset fault threshold upper limit, judging that the power switch device is abnormal; otherwise, judging that the power switch device is normal.