GB/T 5990-2021 is for the detection of refractory properties. The standard adopts the hot wire method and specifies the test method for measuring the Thermal conductivity, specific heat capacity and thermal diffusion coefficient of refractory materials in detail. It is clearly stated from the selection and installation of test equipment to the specific operation process, such as sample preparation, test steps, data processing, etc. With the help of this standard, the thermal performance parameters of refractory materials can be accurately obtained, providing a key basis for their rational selection and optimization design in industrial kilns, high temperature equipment and other fields, and helping to improve the application efficiency of refractory materials.