The invention discloses a three-dimensional reconstruction method and system in intelligent transportation. The three-dimensional reconstruction method comprises the steps of obtaining information of a detection scene, achieving extraction and dynamic tracking of target feature points in the detection scene, achieving feature point automatic completion and conducting three-dimensional reconstruction on targets through a distribution reconstruction algorithm. The three-dimensional reconstruction method comprises the following steps of S101, carrying out camera calibration, S102, synchronously obtaining original video images with scene depth information, S103, tracking feature points of the targets in a video scene, S104, selecting video key frames, S105, reconstructing the selected frames, S106, packaging subsets, and S107, obtaining a final three-dimensional model. According to the three-dimensional reconstruction method and system in intelligent transportation, an improved KLT tracking algorithm is adopted, a feature point model is optimized, and tracking efficiency is improved; the key frames are extracted to serve as the subsets, and the subsets are reconstructed and finally are merged, so that the problems that the obtained video frames are relatively short, and depth obtaining of image information is influenced by tracking losing of feature points in the scene, faults and the like are solved.