The invention belongs to the field of semiconductors, and provides a preparation method of an MPS
diode and the MPS
diode, and the method comprises the following steps: forming a second epitaxial layer on the upper surface of a first epitaxial layer; a third epitaxial layer is formed on the upper surface of the second epitaxial layer, the
doping concentration of the third epitaxial layer is smaller than that of the second epitaxial layer, and the
doping concentration of the second epitaxial layer is larger than that of the first epitaxial layer; a drift
doping region is formed in the third epitaxial layer, and the depth of the drift doping region is larger than the thickness of the third epitaxial layer; and forming an
anode metal layer on the upper surfaces of the third epitaxial layer and the drift doping region, and forming a
cathode metal layer on the lower surface of the first epitaxial layer. When the MPS
diode is turned on in the forward direction, the resistivity of the MPS diode is low, when the MPS diode is turned on in the reverse direction, the second epitaxial layer and the third epitaxial layer are in a high-resistance state, the surface
electric field intensity distribution below the
anode metal layer can be reduced, and the problem that the leakage current of the MPS is large is solved.