A coating method applied to perform coating with liquid metal thermal grease and a heat dissipation module are provided. The coating method includes: providing liquid metal thermal grease on a surface of an electronic element, and scraping the liquid metal thermal grease by a scraper, to coat the surface of the electronic element with the liquid metal thermal grease. A surface of the scraper is roughened. According to the coating method, the surface of the electronic element is evenly coated with the liquid metal thermal grease effectively.