By the influence of the environmental loads and the material characters, propagations of mechanical components' fatigue cracks usually have stage act. In each stage, the cracks propagate with different behavior features. For studying the behavior features and getting a method to predicting the stage transition, time series analysis method was utilized to process the vibration acceleration data, which were recorded to make identification and prediction for the fatigue crack growth behavior patterns in the fatigue test of engine crankshafts. By comparing with the test results of crack growth rate, the prediction capability of the time series analysis method for crack growth behavior pattern was verified.