Abstract: Quasi-static uniaxial tension and cyclic loading/unloading tests of the sutured 3D-C/SiC braided composites were carried out to research the effects of cycle loading/unloading behavior on the damage and inner energy dissipation. Through the fractography analysis of this material, the effect law of the strength change caused by cycle loading/unloading has been explored. The results show that the behavior of cycle loading/unloading will consume energy of interface between matrix and fiber bundle inside the material, resulting in damage to it, which reduces the load-bearing capacity of the material, and the area of hysteresis loop increases as the stress of each unloading point increases. The overall failure of this material is brittle failure, but the fracture of the sample shows obvious delamination under monotonous loading and cycle loading, while the fracture of the uniaxial tensile specimen is more uniform.