The invention provides a magnesium-silver-copper coating for a medical implant material and a preparation method of the magnesium-silver-copper coating in order to solve the problems of synosteosis and infection of an the implant material. The multi-arc ion plating technology is adopted, the metal magnesium-silver-copper coating is prepared on an entity or a porous structure base body made from titanium, titanium alloy, stainless steel and a high polymer material, and the thickness of the coating ranges from 0.1 micrometer to 200 micrometers; and the mass percent of silver in the coating is larger than 0% and smaller than or equal to 10%, and the mass percent of copper is larger than 0% and smaller than or equal to 2%. The permanent implant material with the coating is suitable for the mechanical performance requirements of multiple implanting positions, and has excellent biocompatibility and a sterilizing function.