Through dynamic time warping analysis to the hot-fire test data and simulated fault data of a certain liquid rocket engine, the warped path sets were obtained. Combined with the decision tree method, fault detection and diagnosis were carried out. Results show that there were no failing report and no misstatement for fault tests, and no misstatement for normal tests. Compared with those results by ANN and SVM methods, the successful application of the dynamic time warping method combined with decision tree was proved.