Abstract: The South China Historical Trail has left a lot of cultural heritage, which is of high historical, artistic and scientific value, but the historical buildings are seriously damaged. In order to promote the activation and utilization of the South China Historical Trail, this paper adopts fine 3D modeling technology and VR technology to realize the digital protection of the South China Historical Trail. First, analyze the ruins in South China Historical Trail. Then describe the process and method of fine 3D modeling and VR scene construction for historical relics from the data collection, point cloud data processing, geometric model processing, texture mapping and other aspects. To improve the efficiency of cloud data processing an euclidean clustering point cloud segmentation algorithm based on genetic algorithm is proposed. The application results show that the 3D model and VR scene constructed in this paper can effectively restore the monuments in South China Historical Trail. It provides a new way of thinking for the protection of historical trail, ancient streets, ancient villages, red revolutionary sites and other cultural and natural landscapes.

Key words: the South China Historical Trail, 3D modeling, point cloud data processing, VR scene construction, historical building protection