To scan the large scale architectures should not only choose the appropriate scanning tool, but also, consider the amount of laser scanner station in the process of scanning. The amount of laser scanner station would directly affect the cost and benefit of whole scanning process. The 3D laser scanner was selected as the scanning tool to the Round House of National Quemoy University, and 3D sphere marker used as the conjugated marker between neighborhood scanning stations. Two scanning approaches were proposed in this article, i.e. the most efficient way and the general way of scanning. According to the experiment result, while scanning the large scale architecture, the most efficient way can extend the scanning distance and take less time and stations, also achieve the same accuracy as the general way.