The invention relates to an unmanned aerial vehicle navigation map construction system based on an image three-dimensional reconstruction technology. The unmanned aerial vehicle navigation map construction system comprises an unmanned aerial vehicle, a data acquisition assembly and a three-dimensional navigation map construction system, wherein the three-dimensional navigation map construction system comprises an image set input system, a feature point extraction system, a sparse three-dimensional point cloud reconstruction system, a dense three-dimensional point cloud reconstruction system, apoint cloud model optimization system and a three-dimensional navigation map reconstruction system. A scene image set is input into a three-dimensional navigation map construction system, feature point detection is carried out on all images, and a sparse point cloud model of a scene and a dense point cloud model of the scene are reconstructed, and then miscellaneous points of the models are removed, and surface reconstruction is carried out, and optimization is carried out, and a three-dimensional navigation map of the scene is reconstructed. The invention further discloses an unmanned aerialvehicle navigation map construction method based on the image three-dimensional reconstruction technology. According to the unmanned aerial vehicle navigation map construction method, the three-dimensional navigation map is constructed by utilizing the system, and the reconstructed three-dimensional navigation map is close to a real scene, and the precision is relatively high.