The invention relates to a preparation technology of a turbine though-flow part coating against solid particle erosion, which comprises the following steps that: a coating against solid particle erosion is prepared by hypersonic flame spraying, hypersonic flame spraying equipment is adopted, and a hypersonic flame spray gun is matched, Nir metal-ceramic powder is sprayed on the surface of the turbine through-low part through the process of the hypersonic flame spraying, and high polymer hole sealing agent of polyurethane or acrylic base is sprayed on the outer surface of the coating by adopting a blast atomizer to carry out the sealing processing on the coating. Since the hypersonic flame spraying coating preparation against the solid particle erosion is adopted, the invention can realize large area surface protection of the turbine through-flow part within a short period of time, vibration properties, steam-driven properties, strength properties of the turbine through-flow part are not changed after the spraying protection, and the invention has the advantages of strong field controllability, remarkable improved properties of preventing solid particle erosion and the like, can solve and improve the problem of the solid particle erosion in the existing power station turbine through-flow part on site, and can improve the safety and efficiency of the unit operation.