Multiple square loops-string dome is a newly suspen-dome structure，and cable failure shows significant effect on multiple square loops-string dome structures. This paper used the Fuzhou Strait Olympic Center Gymnasium as the research background to study the effect of cable on the vertical stiffness of the roof，the internal forces of the roof and the ultimate bearing capacity，and safety capability evaluation of the cable failure roof was carried out. The analysis results show that the vertical deformation of the roof can be reduced after cable failure. Among them，the failure of the outer loop cable causes the maximum vertical deformation. However，various vertical deformation distributions subjected to different cable failure are generated. The failure of either the outer loop or string cable can increase the tension force of the adjacent cable significantly. The interaction between the outer loop cable and string cable is greater than the mutual influence between the other loop cables; Ultimate bearing capacity of the roof can be reduced when cable failure occurs，which reaches the minimum value when the outer loop cable fails. It should be noted that “Only one side string cable failure” causes more serious deflection and less ultimate bearing capacity when compared with“two side string cable failure”. In all，failure of the outer loop cable is the most serious case，which causes that vertical deflection increases by 134%，the cable tension force of adjacent cable increases by 11.7%，and the ultimate bearing capacity reduces by 35%. However，the residual roof structure is still in a safe state.