The ISO 26423 standard specifies a method for determining the Coating thickness of fine ceramics (including advanced ceramics and advanced technical ceramics) by crater grinding method. This method calculates the thickness of the coating by performing precise crater grinding on the coating surface, removing the coating material, and then measuring the depth of the formed crater. This method is suitable for thin and high-precision coating measurement, especially in the ceramic field. The standard provides the detailed operation process and technical requirements of Coating thickness measurement, ensuring the accuracy and conformity of the test results, which is of great significance for the quality control and research and development of ceramic materials.