1. A video classification method, comprising: segmenting a video in a sample video library according to a time sequence, to obtain a segmentation result; generating a motion atom set, wherein the sample video library comprises at least one video, and wherein a motion atom in the motion atom set is generated according to the video in the sample video library; generating, using the motion atom set and the segmentation result, a descriptive vector corresponding to the video in the sample video library; and determining, using the descriptive vector, a to-be-detected video whose category is the same as that of the video in the sample video library.