Multi-sensor fusion is an effective way to improve intelligent vehicle perception. For the data-matching problem of the three types of sensors of LiDAR， millimeter-wave radar， and camera， traditional methods such as bipartite graph matching can’t achieve high precision， with poor matching robustness. Therefore， a multi-sensor data fusion algorithm for intelligent vehicles based on tripartite graph matching is proposed in this paper. The problem of data matching of the three sensors is abstracted as a weighted tripartite graph-matching problem. By using Lagrange relaxation， the original problem space is decomposed into subspaces， the weights of vertices and edge inside which are determined then by the cost matrix model. Furthermore， combining the perceptual error model and likelihood estimation， the posterior distribution of perceptual errors is determined. Ultimately the Lagrange Multiplier （LM） model is used for data matching. Finally， the effectiveness of the proposed matching algorithm is validated by the nuScenes training dataset and real-world vehicle tests. On the dataset， the proposed algorithm improves F1 scores by 7.2% compared to common algorithms. In various real-world vehicle scenarios， the proposed algorithm shows excellent perceptual accuracy and robustness across.