Abstract: An algorithm of conflict prediction available for the condition of trajectory change was put forward concerning the problem of how to detect the latent conflict between airplanes in flight efficiently. It calculates the conflict probability to realize the conflict prediction due to the uncertainty of actual trajectory positions. Ameliorated from the prediction algorithm which is only applicable for flight along straight-line fairway, it made the best use of intent information provided by ADS-B to compute the trajectory change point and trajectory change angle, calculated the error covariance matrix of the changed trajectory by matrix transforming, and simplified the expression of the increased error by approximating all angle conditions into two entries: small change angle and huge change angle to ultimately get the conflict probability. The monte-carlo simulation results testify the veracity and precision of the algorithm, the comparison with the algorithm for straight-line fairway indicates the adaptability to more complicated environments.