A　complete　method　to　stitch　multiply　videos　captured　by　USB　cameras　to　form　a　video　with　a　large　field　of　view　in　real-time　is　proposed　in　this　paper.　The　method　includes　the　following　processes:　Firstly,　we　extract　the　video　frames　by　DirectShow.　Secondly,　we　use　the　improved　SURF　algorithm　for　image　registration.　The　improved　SURF　algorithm　restricts　the　scope　in　the　step　of　feature　point　extraction　and　improves　the　original　ratio　method　in　the　step　of　feature　point　matching.　The　improved　algorithm　can　greatly　speed　up　the　process　and　improve　the　accuracy.　Finally,　we　only　calculate　the　transformation　of　the　first　frame　and　use　the　calculated　transformation　matrix　to　stitch　the　other　frames,　which　can　greatly　accelerate　the　speed　of　the　video　mosaic.　The　experimental　results　demonstrate　that　this　method　has　superior　quality　of　video　stitching.