The Monte Carlo (MC) method is widely used in simulating light propagation in skin tissues. A tetrahedron-based Monte Carlo (TMC) method is developed. Energy deposition error due to numerical dissipation can be avoided by the definition of distance threshold. Laser propagation in a two-layered skin model with single blood vessel is simulated to compare geometry-based MC (GMC), voxel-based MC (VMC) and TMC. In GMC, the interface is defined mathematically without any discretization. It is the most accurate but not applicable to more complicated domains. The implement of VMC is simple but it may lead to non- neglected error due to zigzag polygonal interface. TMC provides balance between accuracy and flexibility in the treatment of photon-boundary interaction by the boundary adaptive tetrahedron cells. Numerical results reveal that space adaptability of geometrical shape of TMC is much stronger than that of VMC. Photon energy deposition error by TMC in complex interfacial region is 10%~25% of that by VMC. These results show that TMC is superior in the discretization of tissue boundaries.