Abstract: UAV tilt photogrammetry technology comprehensively perceives complex scenes in a high-precision, high-efficiency, and large-scale manner, which recovers the three-dimensional scene through professional data acquisition equipment and modeling software, and then performs the measurement. Most of the three-dimensional mapping software on the market is based on orthogonal principle of facade scattered points, which cannot effectively reduce the errors caused by manual stereo mapping. This paper proposes a method of weighted least squares line to optimize the vectorization precision of the tilt photogrammetry model. Some areas of Nanchang Sanghai Management Committee of Nanchang city are selected for topographic map data collection and accuracy assessment in this paper. Experiments show that the accuracy of the stereo mapping model is improved by two centimeters through the method.

Key words: oblique photography, three-dimensional model, weighted least squares, straight line fitting, stereo mapping