Abstract: The multi-layer plate specimens of a modified carbon/carbon composite were subjected to fatigue tests for a certain number of cycles at a stress ratio of 0.1 and -1, and then were subjected to uniaxial tensile tests to measure average residual strength of the composite. The specimen with regular penetrating cracks after fatigue was selected. On the basis of crack morphology of the specimen, a finite element calculation model was established in Abaqus software, and the critical stress intensity factor of the specimen was calculated. By using the critical stress intensity factor as a fracture criterion, the residual strength of the remaining specimens was predicted and compared with the measured residual strength of each remaining specimen. The results show that the fatigue cracks on fracture surface of the specimens were all I-type fracture mode, and the average residual strength at the stress ratio of 0.1 and -1 was 252.3 MPa and 258.8 MPa, respectively. The critical stress intensity factor of the specimen with regular penetrating cracks after fatigue was 630 MPa·mm^1/2. The relative errors between the predicted residual strength and the measured values of the remaining specimens were all less than 5.5%, indicating that the prediction accuracy of this method was high.