Abstract: The weakness of 3DEC software in the pre-processing of building the landslide model limits its application. As for this, this paper proposes a new modeling method for complex landslide with MATLAB. Firstly, the terrain maps before and after landslide are used as data sources. Using Distmesh toolbox to triangulate the landslide area, the triangular prisms are generated through an elevation-based interpolation algorithm and to reconstruct the sliding bed and the sliding mass. At the same time, the base material on the sliding path is modeled with Voronoi polyhedrons generated with Multi-Parametric Toolbox. Then, some functions are written to obtain the topology information of these blocks. According to the syntax rules of 3DEC, it is transformed into a command text file that can be received by 3DEC. By this way, the complex landslide model can be established quickly. Finally, taking the Xinmo Landslide in Maoxian County of Sichuan Province as an example, the modeling steps are described in detail. The result of numerical simulation shows that the model established by this method can well reproduce the sliding process, the entrainment of substrate material and the final deposition. The feasibility and practicability of this approach is verified.