GB/T 1965-2023 specifies the method for determining the flexural strength of porous ceramics at room temperature, clarifying the test principle, specimen preparation, operational procedures, and result calculation. It is applicable to the performance evaluation of various types of porous ceramics. The standard adopts the three-point bending method as the primary approach, supplemented by the four-point bending method. By applying a bending load to standard-sized specimens until fracture, the maximum stress is measured to characterize the material's mechanical properties. The test requires the use of an electronic universal testing machine with an accuracy level of Class 1 or higher, equipped with specialized bending fixtures, and combined with high-precision calipers and other measuring tools to determine specimen dimensions. This ensures the accurate collection of data on load, displacement, and dimensions, providing a unified technical basis for the research and development, quality control, and engineering application selection of porous ceramics.