The invention relates to a harmonic transmission modeling method of an electromagnetic current transformer. The harmonic transmission modeling method comprises the following steps: obtaining a primary-side harmonic current signal of the current transformer, detecting a primary-side harmonic current effective value and circuit transformer remanence, ensuring that a hysteresis loop model based on improved J-A is the hysteresis loop model associated with primary current frequency change information, obtaining secondary current corresponding to each component signal of a secondary side of the current transformer after hysteresis loop model transmission is carried out, obtaining an effective value generated after the secondary current is transmitted, and calculating the ratios of transformation of the current transformer under different frequencies. The harmonic transmission modeling method which is put forward by the invention can realize conversion simulation from primary current to secondary current under different frequencies, and improves metering and measurement accuracy under a harmonic condition.