Preparation method of wear-resistant and corrosion-resistant laser cladding repair layer on surface of roller

The invention discloses a preparation method of a wear-resistant and corrosion-resistant laser cladding repair layer on the surface of a roller. The preparation method comprises the following steps: blending basic Ni alloy powder; blending to assist in generating in-situ authigenic reinforced phase powder, and proportioning B4C powder and Ti powder according to the molar ratio of B4C to Ti being 1: (5-3); adding auxiliary generation in-situ synthesis reinforced phase powder into the basic Ni alloy powder; mixing and drying the prepared powder; adding the dried powder into a 5% PVA solution, preparing the mixture into paste, coating the surface of a to-be-repaired roller with the paste, and forming a prefabricated layer; and the coated prefabricated layer is subjected to laser scanning cladding and then naturally cooled to the room temperature, removing a black oxide layer on the surface of a cladding layer, and then polishing the cladding layer to be flush with the original surface of the roller. By means of