Given the intricate design of tower facades, generating 3D models from a single data source often results in regional voids and exaggerated textural details. To address these issues, this paper proposes a 3D modeling method for tower buildings by integrating and synthesizing data from Unmanned Aerial Vehicles (UAV), airborne LiDAR, and handheld LiDAR. Illustrated by the case study of the vibrant Wucailou building in Xinping County, Yuxi City, Yunnan Province, data acquisition is conducted using UAVs and handheld laser scanners. Initially, separate collections of UAV imagery, airborne LiDAR, and handheld LiDAR data for the tower are undertaken. Subsequently, UAV image point clouds are generated adhering to photogrammetric principles. And then the three kinds of data are fused with alignment based on the nearest-point iteration algorithm method, and finally, the three kinds of data are fused with alignment by constructing a irregular triangular mesh to represent its 3D model. The experimental results validate that the 3D model derived from the harmonized multi-source LiDAR and UAV image data is more complete, which avoids the problem of voids that exists in the construction of 3D models from a single data source.