This standard establishes a standardized testing procedure for determining the pore size distribution and porosity of solid materials using the mercury intrusion method. It provides a critical technical basis for characterizing the microstructure of materials in fields such as porous ceramics, catalysts, building materials, and battery separators. The core principle relies on the non-wetting property of mercury toward most solids. By precisely controlling the applied pressure to force mercury into the pores of the sample, and establishing the correspondence between pressure and pore size according to the Washburn equation, key parameters such as pore volume, pore size distribution, and porosity of the material can be analyzed. In practical testing, fully automated mercury intrusion porosimeters are primarily used to perform the analysis. These instruments can provide pressures up to approximately 400 MPa, covering a broad pore size detection range from the nanometer to micrometer scale. They are equipped with advanced vacuum and sensing systems to ensure the acquisition of high-precision and highly reproducible test data under stringent safety protocols.