A method and an apparatus are provided for obtaining a motion vector, and disclose application of the method and the apparatus for obtaining a motion vector in a video coding method and apparatus. The method includes: obtaining a first motion vector from a first motion vector set corresponding to a to-be-processed picture block; obtaining a second motion vector through calculation based on the first motion vector, where there is a preset vector difference between the first motion vector and the second motion vector, and the first motion vector and the second motion vector are different; adding the second motion vector to the first motion vector set to constitute a second motion vector set; and obtaining a target motion vector from the second motion vector set.