Abstract: Based on the large-scale mapping technology of the 3D model of the UAV tilt photography, the large-scale mapping system is developed by using innovative techniques such as data denoising optimization, main baseline extraction and optimization. The system can solve the problems of large workload, large buildings in the old city, intensive conditions in the old city, closedness and privacy of the residents, complicated procedures and high cost in the conventional full field digital mapping method. Set strict rules and thresholds to eliminate gross errors and optimize combinations, ensure the quality of the baseline, ensure the accuracy of surveying and mapping results, and the level of research and development has reached the domestic advanced level.

Key words: unmanned aerial vehicle, tilt photography, three-dimensional model, main baseline, auxiliary baseline, large scale mapping