For the two types of domestic T800-grade carbon fibers，which T800 made by wet spinning and SYT55 made by dry-jet wet spinning，the microstructure of the carbon fibers was characterized by using a scanning electron microscope.Both types of carbon fibers were combined with bismaleimide resin 802 to prepare hot-melt prepreg and carbon fiber/bismaleimide composites.The tensile，compressive，and shear mechanical properties，as well as the microscopic failure morphology，were tested and analyzed.The results show that the surface of SYT55 fiber is smooth， and its carbon fiber/bismaleimide resin composite has higher tensile strength and good high-temperature mechanical properties.The TG800 fiber composite has higher interfacial strength.