The traditional aeroengine residual life prediction method assumes that all aeroengines have the same performance deterioration pattern in a fleet, which leads to a low prediction accuracy. On the basis that the aeroengine exhaust gas temperature margin (EGTM) is analyzed, the aeroengine residual life prediction method based on performance deterioration pattern is proposed. The gross error removal of aeroengine EGTM time series data is studied. The distance measure of aeroengine EGTM time series data is defined, and performance deterioration pattern mining steps are given. Finally, the CFM56-5B aeroengine EGTM time series data is adopted to verify the proposed method. The results show that the average absolute relative error of the proposed method is reduced by 2.5％ compared to the method of average EGTM deterioration pattern in a fleet. Thus, the aeroengine residual life prediction method based on performance deterioration pattern can supply reliable support for predicting aeroengine removal deadline and making maintenance plan.