Aiming at the problem of the limited number of measuring points in traditional bridge monitoring methods, a method for obtaining holographic geometric information of bridges through photogrammetry was proposed to realize the monitoring of arbitrary point displacement of the whole bridge. First, the morphological image data acquisition system is used to obtain continuous photos of the test beam with repeated regions, and then the continuous pictures are stitched based on the improved SIFT algorithm to obtain the test beam hologram. Extract the holographic deformation curve of each test beam. By comparing with the displacement results obtained from the traditional displacement meter measurement and the SIFT algorithm, it is found that the stitched image based on the improved SIFT algorithm contains rich information, which can lay the foundation for the monitoring of holographic geometry in the application of large-scale structures and large fields of view.