In order to study the stray-field loss properties of the transformer structural parts under various dc biased condition, which are made of the magnetic steel plate(Q235B), a test model with compensator of leakage flux is proposed and manufactured in this paper. The distribution of stray-field loss is investigated in detail based on the test model. The different electromagnetic behavior of the magnetic steel plate under the interaction between the ac exciting source and the dc exciting source is also examine...