Aiming at the safety hazards and various collision problems in the construction process of transmission line tension release, this paper proposes a simulation method of transmission line tension release construction process based on laser point cloud. Firstly, the 3D point cloud data of the transmission line construction site is collected by airborne LiDAR, and the normalized elevation threshold filtering algorithm is used to segment the point cloud data to obtain ground and non-ground points, and the tower points are coarsely extracted according to the spatial dimensional features of the point cloud; then the point cloud of a single transmission tower is extracted with high precision by using the improved K-Means algorithm to cluster the center of the body elements; according to the laser point cloud, the laser point cloud is used to BIM technology is used to reverse model the target equipment and construction environment to build a digital 3D real-world model of the construction site; finally, the virtual prototype technology is used to establish a 3D real-world tension release system for transmission lines to simulate the dynamic process of tension release at the construction site and realize the construction process control, safety exploration and hazard point analysis. Results demonstrate that this method can effectively and accurately simulate the tension release construction process on-site with a numerical error within 5%. This provides reliable data support for precise construction, process control, and safety survey of tension release, indicating its significant engineering value.