We propose a multi-line laser simulation system utilizing computer graphics and physical simulation to generate virtual multi-line laser datasets. Our framework provides key physical properties of the scene, including camera parameters, depth values, surface normals, and the actual two-dimensional (2D) and three-dimensional (3D) coordinates of the laser stripe centers for each rendered image. Beyond, we construct a virtual line laser scanning image dataset with a complex background by simulating interactions between lasers and object surfaces with the Monte Carlo method. With the proposed framework and dataset, a multi-line laser extraction algorithm based on a robust sorting algorithm is proposed and tested, which utilizes distance-based error analysis, connected component labeling, and iterative optimization refinement techniques. Both simulation and actual experiments show that our method outperforms the other state-of-the-art multi-line laser stripe center extraction methods. The proposed framework can be applied to different types of laser scanning systems in the future.