The invention discloses a method for classifying motion data actions based on DTW curved line. The method comprises the following steps: (1), a bidirectional DTW distance and a partitioned DTW distance which are used for measuring similarities among movement sequences are produced; (2), a DTW curved line is produced according to the bidirectional DTW distance and the partitioned DTW distance, wherein, W EoLC is a logical division validity curved line, D s-dtw is a partitioned DTW distance, lambada is a threshold value used for partitioning, and P and Q represent two movement sequences; and (3), hierarchical clustering algorithm is adopted for classifying the movement sequences according to the valid weighted distance obtained from step (2). The method of the invention relaxes the restriction on DTW, so that the classification robustness is enhanced, and experimental results show that the method of the invention can ensure that better classification results can be obtained.