A manufacturing method of transformer circuit board includes following steps: plate stamping, forming a plurality of metal plates with a stamping mold; primary layering, layering the metal plates that are in alignment with each other between two outer insulation layers, with an inner insulation layer disposed between the two metal plates; primary pressing, hot pressing the metal plates to fix the metal plates between the two outer insulation layers; secondary layering, layering another metal plate on the outer side of the two outer insulation layers, respectively, corresponding to the positions of the previously layered metal plates; secondary pressing, hot pressing the metal plates on the outer side of the outer insulation layers, and printing to form a solder mask layer on the outer insulation layers. Finally, cutting to form a transformer circuit board with low leakage inductance and high EMI shield.