GB/T 39713-2020 is a recommended national standard for the specific surface area testing of fine ceramic powders, which clarifies the core content of term definition, principle, test steps, data processing and reporting. The standard adopts the low-temperature nitrogen adsorption BET method, which is suitable for the physical examination of fine ceramic powders in the range of 0.01 m ²/g to 2000 m ²/g. The specific surface area can be accurately calculated with the help of the multi-layer adsorption characteristics of gas molecules. The test process requires the use of a fully automatic BET Surface Area Analyzer, which measures the adsorption isotherm through the static capacity method, and completes the data calculation in combination with special software, providing a unified and reliable detection basis for the quality control, research and development and application of ceramic powder materials.