Abstract: Video compositing is to combine multiple video screens into a video screen， it is an important issue in the digital video editing. Adobe Premiere CS4 video editing software, offers a variety of techniques to address this issue. This paper introduces through adjusting the transparency of the material or setting a video clip of "mixed mode" to complete the video compositing; Using video effects filters can cutout, according to the material color, brightness, garbage matte, in order to achieve the purpose of video synthesis; And uses "the track matte key" effects to enable tracking screen video compositing techniques. Practice has proved that the flexibility to use these methods to produce efficient, natural digital video productions.

Key words: video compositing technology, opacity, Alpha channel, cutout, track matte key