Amorphous specimens of Fe78Si9B13 have been treated by ultrashort pulse current. It was obtained that the α-Fe(Si) single-phase structure precipitated from the amorphous matrix of Fe78Si9B13 by adjusting the parameters of pulse current. It can be considered that the single-phase crystallization results from the periodic repulsion between the moving electrons and the vacancy-like structural defects in the amorphous parts.That is,the repulsive effect causes the metalloid atoms B to precipitate from the amorphous structural units and Fe(Si) atoms segregate in some localized region. So the basic metal phase is forced to nucleate at a lower temperature. However the directional migration of vacancy-like defects will be accompanied by diffusion of atoms B. Obviously,the segregation of atoms B and the precipitation of Fe-B compound will be checked by both factors the mentioned above.