The invention discloses a silicon carbide MOSFET (metal-oxide-semiconductor field-effect transistor) channel self-alignment process realization method. The method includes the following steps that: a silicon carbide epitaxial wafer is washed; a first dielectric layer is deposited on the silicon carbide epitaxial wafer; a second dielectric layer is deposited on the first dielectric layer; the second dielectric layer is coated with a photoresist, and a primary P type base region window is formed through photolithography development; SiO2 dielectric is etched with the photoresist adopted as a mask; with residual photoresist and the SiO2 combined together and adopted as a mask, polycrystalline silicon is etched, and after etching is completed, and residual photoresist is removed; with the polycrystalline silicon adopted as an ion implantation barrier layer, aluminum ion implantation is performed, so that a P type base region can be formed; SiO2 is deposed on the polycrystalline silicon, and then is etched, so that a sidewall mask can be formed; with the polycrystalline silicon and the sidewall adopted as an ion implantation barrier layer, nitrogen ion implantation is performed, so that an N<+> source region can be formed; the SiO2 and the polycrystalline silicon are removed, and a P<+> ion implantation barrier layer can be formed; and aluminum ion implantation is performed, so that a P<+> contact region can be formed. According to the silicon carbide MOSFET channel self-alignment process realization method of the invention, the polycrystalline silicon is deposited, and the sidewall is formed, and the polycrystalline silicon and the sidewall are adopted as the P<+> contact region barrier layer, so that nitrogen ions will not be implanted in the P<+> contact region, and a stripping process is not needed.