With the development of technology, 3D laser scanning technology has some advantages in data acquisition of buildings. Baling Bridge in Weiyuan County of Gansu Province is a unique pure wooden overhanging laminated beam arch bridge in China. This bridge has long enjoyed a good reputation because of its excellent construction of artistic and scientific values. Taking Baling Bridge in Weiyuan County as an example, based on 3D laser scanning technology, the point cloud data of the ancient bridge are acquired and processed, and relying on the point cloud data, the digital protection of the urban ancient bridge is applied and discussed.