In order to analyze the robustness of spatial truss structure and prediction method of structural failure, the member key coefficient was introduced calibrate the stress rate method by considering structural catenary effects on element’s failure to predict structural failure model and structural reliability analysis. A single layer start dome was numerically simulated by ANSYS, its structural failure model was analyzed by comparing curves of stress rate by classical and improved stress rate methods under static step load and vertical seismic loads. As the contrast analysis, finite element analysis software ALGOR was applied in the analysis of a new type of truss string structure to calculate the structural sensitivity coefficient under 7 partial failure conditions, by which the structural robustness analysis was conducted and compared with traditional truss string structure. The results showed that, the stress rate before the structural critical failure was significantly increased by considering member key
coefficient, which could be used to predict structural failure. By changing the numbers and arrangement locations of cables, the structural failure sensitivity was significantly reduced and the structural reliability was greatly improved. Under the cable broken conditions, the resist progressive collapse of the new type truss string structure was improved and the process from partial damage to collapse was prolonged. And the structure safety is improved and the structural capability of resisting disaster loads was enhanced.