Abstract: Aiming at the problems of low flight safety, data redundancy, and poor quality and accuracy of constructing 3D models in different terrain environments. This paper uses single-lens quad-rotor small UAV as the experimental equipment. To the complex single building in flat terrain environments uses tic-tac-toe cross routes and circumferential routes. To the mudslide gully in complex mountain terrain environments uses horizontal routes, tic-tac-toe crossing routes, and video routes to construct the 3D model. Combined with route parameters, 3D model quality accuracy, the influence of the UAV route planning scheme on 3D model construction under different terrain environments is discussed. As indicated by the results, used the circumferential route could safely and quickly acquire images of complex single building in flat terrain, and construct a complete, good quality, and accurate 3D model.Used the tic-tac-toe cross routes can construct a complete, good quality, and accurate 3D model of the mudslide gully in mountainous terrain, but the flight safety and timeliness are low. Used the video routes, the image overlap is high, and a complete, high-quality 3D model can be constructed, the accuracy of the model is not significantly different.

Key words: UAV, different terrain, route planning, circumferential routes, video routes, 3D model, evaluation analysis