The determination of burn depth is an important problem for surgeons to remedy severe skin burns. The burn can be simplified as a two-layer media model: a static layer and a dynamic layer. In this paper, the relative fluctuation of backscattering light intensity was used to determine the simulated burn depth. The experimental results show that the relative fluctuation of light intensity increases with the simulated burn depth and the depth less than 0.1 mm can be resolved. This new method may be useful for burn diagnosis.