Abstract: Mechanical coating technique (MCT) as a novel coating formation process was proposed and developed based on mechanical frictional wear and impacts among alumina balls, columns, disks and metal powder particles in the bowl of a planetary ball mill or pot mill. MCT is a simple, low cost and useful coating formation process. Metal coating of Ti, Cu, Ni, Fe and Zn on alumina balls were prepared by MCT. The influence effects of the coating formation were investigated from four views of physical, chemical, mechanical and process factors. The formation process of the metal coatings in MCT includes four stages: nucleation by adhesion, formation and coalescence of discrete islands, formation and thickening of continuous coatings, exfoliation of continuous coatings. Further, 2-stap MCT was developed based on MCT concept for preparing composite coatings on alumina balls. Based on MCT, the fabrications of photocatalyst coatings were summarized, and an outlook to the research direction was discussed.