In order to solve the problems such as crazing deformation and hole caused by missing point cloud in 3D model reconstruction of complex curved buildings, a research scheme combining 3D laser scanning technology and oblique photogrammetry technology is proposed, which is to obtain laser point cloud after the data and the oblique image point cloud data, the two point cloud data are registered and fused. This paper takes a complex surface building as an example, uses the improved SICP algorithm to complete the registration fusion of two point cloud data, and realizes the 3D model reconstruction of the complex surface building through the fusion point cloud data. The experimental results show that the registration and fusion of laser point cloud and oblique image point cloud can effectively construct high-precision and high-resolution 3D models.