Abstract: There is less study on obtaining more realistic 3D model how to optimize building concrete segment. By PhotoScan software, the paper puts forward some techniques of 3D model optimization based on discussing key steps of 3D model building in the studied area. For example texture missing, image distortion, data screening, parameters setting and operating sequence, etc.

Key words: tilt image, 3D model construction, model optimization, PhotoScan software, parameter optimization