This paper proposes a method to utilize 3D point cloud technology for efficient inspection of bridges suffering from aging and deterioration. To overcome the inefficiency of existing manual inspection methods and the limitations of insufficient real data, we present a systematic framework to automatically generate complete 3D bridge data. The framework generates complete point clouds with component-level instance annotations, high-fidelity colors, and precise normal vectors, and simulates various physically realistic incomplete point clouds to support the training of segmentation and completion networks. Experimental results show that the PointNet++ model trained with synthetic data achieves 84.2% mIoU in real bridge semantic segmentation, and the fine-tuned KT-Net shows excellent performance in component completion. This provides an innovative methodology and a basic dataset for 3D visual analysis of bridge structures, which has important implications for the advancement of automated infrastructure management and maintenance.