The invention provides a preparation process of an inorganic copper imitation coating and a process for replacing a protective and decorative copper layer of a metal surface with the inorganic copper imitation coating, and belongs to the field of metal protection and decoration. The preparation process of the inorganic copper imitation coating comprises the following steps of: by taking potassium silicate and silica sol as adhesives of the coating, adding fumed silica as filler of the coating to a mixed solution of potassium silicate and silica sol; then adding a silane coupling agent and a wetting dispersant as assistants used for improving the coating performance; finally adding antique brass pigment fillers to obtain the copper imitated inorganic silicate coating. The coating prepared by the method can replace the protective and decorative copper layer of the metal surface, and is applicable to the field of metal protection and decoration. The inorganic copper imitation coating prepared by the method is high in protection and decoration performance, avoids galvanic corrosion caused by the copper layer, saves the protection cost, has performance superior to a copper coating, and also has the advantages of being low in cost, environment-friendly, high in corrosion resistance, high in cohesion, etc.