Abstract: Semiconductor numerical simulation based on the finite volume method has unique requirements for mesh generation, including solving the interference problem of basic voxels in geometric inputs, controlling large- scale grid sources. This paper proposes an automatic hybrid mesh generation method for the needs of semiconductor device simulation. It used a surface mesh repair algorithm and a feature recognition algorithm to solve the interference problem of basic voxels, repair and reconstruct a clean boundary representation model, and improve the mesh quality. By building an octree, it managed large- scale grid sources to achieve rapid control of mesh size and scale. It used the sweeping method to generate anisotropic structured hexahedral mesh units in the featured areas, and used the Delaunay triangulation algorithm to generate isotropic tetrahedral mesh units in the non- featured areas to achieve hybrid mesh generation.