Abstract: The in-situ observation method can observe the damage evolution process of continuous silicon carbide fibers reinforced silicon carbide ceramic composites (SiC_f/SiC) in real time, dynamically and continuously, so it is of important academic value and high engineering significance to the study of the safe operation of SiC_f/SiC composites in application. The principles of scanning electron microscopy(SEM), X-ray computed tomography(X-CT), and transmission electron microscopy(TEM) in-situ observation and their advantages, limitations and specimen preparation methods in the study of mechanical damage evolution of SiC_f/SiC composites were introduced firstly. SEM, X-CT and TEM in-situ observation methods have been widely used to analyze microcrack initiation and propagation in SiC_f/SiC composites, as well as the dynamic response process of microstructure to different external excitation signals in recent years. These researches were reviewed. Finally, it was pointed out that X-CT in-situ analysis technology would have a wonderful future in the study of dynamic damage of SiC_f/SiC composite in the future.