Abstract: With the construction of deep underground openings, the formation of excavation failure zone and its prediction have become a focus of rock mechanics in deep underground excavation both in China and abroad. Based on the analysis of mechanical properties of hard rocks during their failure process, the conventional continuum models and the cohesion weakeningfriction strengthening（CWFS）model were compared. Numerical analysis of a circular test tunnel in a Mine-by Experiment at the URL in Canada was carried out by using FLAC with elasticperfectly plastic, elastic brittle, strain softening and CWFS constitutive models, respectively. The results of comparison of stress distribution, principal stress values at key points and plastic region among different models show that CWFS model can simulate the stress transfer and stress concentration to a deep area, which is the real situation when stress-induced failure occurs; the stress distribution calculated from CWFS model is much closer to that when the excavation failure zone is deleted. Compared to other models, the extent and depth of excavation failure zone calculated by CWFS are larger and they are in agreement with the field measurements. Finally, the CWFS model was used to investigate the failure zone in another case, the Kobbskaret road tunnel in Norway. The depth and extent of the excavation failure zone were predicted rather well and it again proves the rationality of using CWFS model in predicting the excavation failure zone of hard rocks in deep tunnels.