This standard specifies the test requirements for the high-temperature mechanical properties of two-dimensional braided quartz fiber fabric-reinforced resin matrix composites. It is applicable to the determination of tensile, compressive, and flexural properties, as well as short beam shear strength at test temperatures not exceeding 500°C. Other similar composite materials may also be referenced. The standard clarifies key aspects such as specimen preparation, testing procedures, and data processing, providing a basis for evaluating material performance under high-temperature conditions. Relevant testing instruments include a high-precision universal testing machine, a high-temperature environmental chamber with a temperature control deviation of ≤±3°C, high-temperature extensometers or strain gauges with an accuracy of at least grade 1, and temperature measurement sensors with an allowable deviation of grade II or higher, ensuring the accuracy of the tests.