1. A motion vector estimation method, comprising: detecting a feature point in a video frame, and performing motion estimation on the feature point to obtain a motion vector of the feature point; using a window region that has the feature point being the center and has a preset pixel size as a feature block, and using the motion vector of the feature point as a motion vector of the feature block; dividing the video frame into image blocks, determining whether an overlapping area between an image block in the video frame and the feature block is greater than a preset threshold value, and if yes, determining the corresponding image block as a feature image block; using a weighted average of motion vectors of feature blocks having an overlapping relationship with the feature image block as an initial motion vector of the feature image block; and calculating a distance between each image block and the feature image block, performing motion estimation on the image blocks in an ascending order of the distances between the image blocks and the feature image block, and using an obtained motion vector of an image block as an initial motion vector of an image block that is adjacent to the image block and has not undergone motion estimation, until motion estimation is completed for the image blocks in the entire video frame.