The decrease of reliability arise from degeneration can’t be neglected. SVR（Support Vector Regression）would be applied to estimate the degree of degradation and loss of flow coefficient based on the data collected from engine. Nonlinear regression of SVM(support vector machine) is proposed kernel function transform method, the feature space optimization to obtain the optimal classification plane. Mann-Kendall test would be used to estimate the trend and speed of degeneration and judge the degeneration from fault. Simulation shows that SVR could estimate the degree of a parameter, and the technologies of Mann-Kendall could distinguish fault and degeneration.