The invention relates to a method of determining magnetic conductive member stray loss, and belongs to a power transformer electromagnetic measurement technology field. According to the technical scheme of the invention, a simulation calculation way is adopted to correct a magnetic conductive member loss measurement result of an electromagnetic device. The magnetic conductive member loss is measured by adopting a conventional load-zero load way, and then the simulation calculation way is adopted to acquire a loss difference between a load working condition and a zero load working condition of an excitation coil, and at last, the loss difference is introduced in the magnetic conductive member loss measurement result, and therefore final loss data is acquired. The method is advantageous in that by adopting the simulation calculation way, a loss difference between two working conditions of a non-magnetic conductive material copper wire is calculated accurately, and the loss difference is introduced in the measurement result to correct the magnetic conductive member loss acquired by the experimental measurement, and therefore the accurate and reasonable loss data is acquired.