Automatic　reconstruction　of　unknown　three-dimensional　(3D)　objects　is　one　of　the　classical　research　in　machine　vision,　which　is　widely　used　in　industrial　inspection,　robot　localization　and　navigation,　reverse　engineering,　and　cultural　relic　restoration　etc.　A　new　approach　of　reconstructing　unknown　3D　models　automatically　is　proposed.　The　new　algorithm　incorporates　the　visual　region　of　the　monocular　laser-vision　system　with　the　limit　visual　surface　of　unknown　model　and　selects　the　suitability　of　viewpoints　as　the　NBV　on　scanning　coverage.　The　limit　visual　surface　is　modeled　by　the　known　surface　data　obtained　from　initial　view　and　is　used　to　predict　the　maximal　unknown　object　surface　information.　Then　the　next　view　visibility　is　determined,　correspondingly　the　visual　rotation　angle　and　translation　zones　are　obtained.　And　the　position　which　can　obtain　the　maximal　visual　surface　area　in　the　visibility　zone　is　selected　as　the　next　best　view　position.　The　experimental　results　show　that　the　method　is　effective　in　practical　implementation.