This standard is a part of the series of standards for fatigue performance testing of polymer matrix composites. It specifically specifies the methods for conducting two important modes of testing: "tension-compression fatigue" and "compression-compression fatigue" under constant amplitude and constant frequency cyclic loading conditions. It provides a unified testing procedure, result processing, and reporting specification for evaluating the durability and lifespan of materials under alternating tensile and compressive loads, as well as repeated pure compressive loads. The core testing instruments for implementing this standard are high-frequency fatigue testing machines or universal material testing machines equipped with dynamic cyclic loading capabilities. These devices must be capable of precisely controlling load and frequency to simulate the alternating stress conditions encountered in actual service.