Abstract: Through uniaxial tensile test of C/SiC ceramic matrix composite connection structure, the change law of mechanical properties of connection structure during pull-off failure was studied. Combined with strain measurement, high-speed camera, CT detection and other test methods, the damage evolution process of the connection structure during the pull-off failure process was explored from the macro and micro perspectives, and the pull-out failure mechanism of the ceramic matrix composite connection structure was determined. The results show that the initial stiffness of different connection structures is inconsistent due to the difference of the deposition and contact state of the thread. As the displacement increasing, the stiffness of the connecting part tends to be consistent. Damage and delamination occur when the threaded hole is squeezed during loading. When the local damage of the threaded hole reaches a certain degree, the connecting structure reaches the maximum bearing capacity. At this time, as the displacement continues to increase, the screw begins to pull out, and the bearing capacity begins to decline until the screw is completely pulled out.