At present, there are diverse data sources and mature technologies for the 3D modeling of cities, and 3D modeling is also developing towards component-level and refined modeling. In this study, we combined the needs of refined management in the central area of Beijing and elaborated on the practice of using various point cloud collection devices to carry out multisource point cloud data collection and ultrafine 3D modeling in areas where flight operations are not possible. There are three main areas of innovation: (1) the development of full-element ground acquisition and multisource point cloud joint 3D modeling technology, which solves the technical problems of acquiring all types of ground scanning data, such as those obtained using static, station-, cart-, backpack-, and vehicle-mounted laser scanning instruments, and handheld scanners, as well as multisource point cloud data fusion and modeling; (2) the development of a vehicle-mounted ultrahigh-resolution image acquisition system, which improves the efficiency of the vehicle scanner by increasing the exposure frequency to enhance its travel speed and (3) the use of tools to automatically extract urban components based on point clouds, which improved the efficiency of 3D modeling and achieved the fine-grained modeling of massive components in the region. On the basis of the system platform, the management and implementation of urban component-level information can be achieved.