The invention discloses a power equipment testing method based on transformer substation mixed electromagnetic interference simulation. The method comprises the following steps of firstly, placing aninsulation support on a grounding panel, and placing tested power equipment on the insulation support; connecting multiple interference signal generators to a power supply port and/or a signal port ofthe tested power equipment; at least selecting the two interference signal generators to apply electromagnetic interference signals to the tested power equipment, so that the tested power equipment is subjected to mixed electromagnetic interference; and observing whether the tested power equipment can normally work or not under the condition of the mixed electromagnetic interference. The method can be used for really and effectively simulating the mixed electromagnetic interference actually received by the power equipment of a transformer substation, thereby being beneficial to accurate evaluation of the anti-interference capability of the power equipment.