Method and system for downloading video by dotting on line

The embodiment of the invention provides a method and a system for downloading video by dotting on line. The method comprises the following steps that: a download request message is received; the download request message carries the starting time point and ending time point for a user to choose a video; the video chosen by the user is dotted according to the starting time point and the ending time point in the download request message, and the fragments of the video are intercepted; and the intercepted fragments of the video are transcoded, output and sent to the user. Through the method, the user can choose to download a video fragment that the user likes or requires by dotting without downloading the whole video, so that the downloading time is saved and the use of the user is convenient.