Abstract: A thermal vibration test was conducted on the connection structure of C/SiC ceramic matrix composite materials based on electromagnetic induction heating and basic excitation vibration methods. The dynamic response of the connection structure at room temperature and high temperature was obtained. The nonlinear mechanical behavior of the connection structure was analyzed and studied using frequency response function, short-time Fourier analysis, and restoring force surface method. The results indicate that the C/SiC specimens demonstrate remarkable nonlinear characteristics, including frequency shift and the presence of high order harmonics. When subjected to a broadband random vibration load with a root mean square (RMS) value of 2 g, as the temperature at the connection site of the C/SiC specimen varies from room temperature to 1300 ℃, the first order frequency of the specimen experiences an increase from 219.8 Hz to 261 Hz. During the process of increasing the RMS value of the narrow band random vibration load spectrum from 0.77 g to 3.46 g, the first order frequency of the specimen decreases to different extents under different temperature states. The augmentation of the vibration level induces substantial deformation of the specimen, thereby resulting in gap - collision phenomena at the connection, which leads to high order harmonics in the dynamic response of the structure. The elastic recovery force - displacement curve, identified through the restoring - force surface method, reveals that the connection stiffness of the C/SiC specimen manifests segmented characteristics. Specifically, the displacement of the segmented inflection point gradually escalates with the increase in temperature, and the segmented stiffness effect becomes increasingly less pronounced. Simultaneously, as the temperature rises, the overall stiffness of the specimen increases. Under high temperature conditions, the thermal expansion and deformation of the connecting parts of the specimen influence the contact between the fasteners, contributing to a more complete and superior performance. These research findings furnish a crucial basis for the dynamic analysis and structural integrity analysis of C/SiC connection structures within a high temperature dynamic environment.