The invention relates to an equivalent method for testing the anti-electromagnetic interference ability of a large current transformer with a stabilizing winding. The method can simulate a stray magnetic field produced by adjacent-phase electrified buses in an iron core of a large current transformer more accurately, thereby equivalently testing the error and temperature rise of the large currenttransformer when working under field conditions. When the equivalent method is implemented, two sections of equivalent windings which are serially connected in a reverse polarity mode and have equal turn numbers are wound on the large current transformer, and the stray magnetic field produced by the adjacent-phase electrified buses from one direction can be simulated by controlling the ampere turns and winding angle of the equivalent windings. A stray magnetic field produced by multi-phase electrified buses arranged at any positions can be simulated by adopting two groups of orthogonal equal ampereturn duplex windings. The equivalent method solves the problems that the anti-electromagnetic interference ability of the prior large current transformer with the stabilizing winding always fails to be effectively tested and detected.