Abstract: In order to improve the reconstruction accuracy of the three-dimensional surface model of the stem and reflect the surface characteristics of the stem, a three-dimensional surface reconstruction algorithm of the stem based on subdivision is proposed. Vertically segments of the stem point cloud are obtained according to the given segment height. On the basis of calculating the centroid of each segment, each vertical segment is divided into several angular partitions according to the given angle parameter, and the center point set of the angular partitions is obtained. A coarse-grained tree stem surface model is obtained using a tree stem 3D surface reconstruction algorithm based on tangent plane projection with the center point set. Based on the improved Loop subdivision algorithm and Sqrt3 subdivision algorithm, the coarse-grained surface model is subdivided to obtain the fine-grained surface model. The experimental results show that the stem surface model reconstructed by the improved Loop subdivision algorithm and the improved Sqrt3 subdivision algorithm can more effectively reflect the unevenness of the stem surface; compared with the improved Sqrt3 subdivision algorithm, the stem surface model by the improved Loop subdivision algorithm has smaller Hausdorff distance. The stem surface model constructed by the proposed algorithms can effectively reflect the irregular geometric features of the stem surface, and the model construction is more accurate. In practical applications, the improved Loop subdivision method should be preferred to reconstruct the stem surface model.