The present invention provides a method and a device for monitoring consistency of track keeping performance. The method comprises the steps of: obtaining a track consistent data collection and a track inconsistent data collection at various times on a planned track according to the planned track of the aircraft; obtaining a predicted deviation distance of the aircraft according to the planned track and a present track of the aircraft; obtaining a aircraft track consistent probability and a aircraft track inconsistent probability within the preset time period after the presentt time accordingto present flight coordinates, the predicted deviation distance, the aircraft track consistent data collection, the track inconsistent data collection and maximum likelihood estimation algorithm; obtaining a result of the aircraft keeping performance according to the aircraft track consistent probability, track inconsistent probability and a preset probability threshold. Making recommendations foraircraft flight timely is possible, and the operational efficiency of air traffic is improved by predicting the aircraft track consistent probability in advance.