Digital　technology,　computer　graphic,　optical　and　mechanically　technology　have　greatly　changed　some　traditional　industries.　1Three　dimensional　(3d)　laser　scanning　technology　is　one　of　the　integrator　of　these　advanced　technologies.　Documentation　and　conservation　of　the　cultural　heritage　in　3D　technology　is　also　widely　recognized　and　applied　at　international　level.　2　Terrestrial　laser　scan　(TLS)　is　the　most　popular　technologies　in　preserving　architectural　heritage　domain,　and　it　is　implemented　on　many　preserving　projects.　3　However,　there　are　some　problems　which　have　blocked　the　application　of　this　technology.　The　most　important　factor　is　the　3D　data　are　hard　to　integrate　in　traditional　method　of　preserving.　Orthographic　map　is　a　very　common　and　frequent　form　of　documents　and　it　can　be　generated　from　3D　data.　This　article　focused　on　large-scale　architectures　and　courtyard-level　scale　heritages＇　3D　scanning　with　Three　dimensional　laser　scanner　based　on　scientifically　calculations,　and　creating　orthographic　map　for　traditional　professionals　and　researches.　The　project　of　this　paper　is　a　part　of　preserving　program　hosted　by　the　Beijing　Municipal　Administration　of　Cultural　Heritage,　which　required　high　efficiency　and　high　fidelity　of　3D　scanning.　The　research　and　experience　will　benefit　others　and　facilitate　the　spread　of　architectural　heritage　digitalization.