The invention relates to a preparation method of a supported Ni-B amorphous catalyst for selective hydrogenation. Ultrasonic waves, spray drying and microwave radiation are respectively introduced into an impregnation-reduction method to prepare the supported Ni-B amorphous catalyst. In the impregnation, drying and roasting process, the invention enhances the dispersity of the Ni precursor in the support and the interaction with the support, greatly improves the catalytic performance of the supported Ni-B amorphous alloy catalyst in the TDA (tolylenediamine) synthesis process by DNT (dinitrotoluene) hydrogenation, greatly shortens the preparation period of the catalyst, and has wide industrial prospects.