In order to improve the efficiency and accuracy of structural transient reliability analysis,based on dimension reduction (DR) and parameter optimization strategy,and support vector machine (SVM) was taken as modeling basis,a hyperparameters optimization support vector machine-based on dimensionality reduction (DRHOSVM) method was proposed.Taking the fatigue life data set of aero-engine turbine disk as the algorithm verification object,the transient reliability analysis was carried out.By comparing with the direct simulation,traditional support vector machine and Kriging,the effectiveness and applicability of DRHOSVM in modeling characteristics and simulation performance were verified.The results show that DRHOSVM has good accuracy and efficiency in high- dimensional data scale,and it is suitable for reliability analysis of complex structures.