提出了一种通过光热法测定与样品表面温度有关的光热信号，重构反映多层不均匀材料中光吸收系数深度分布的理论处理和新的有效数值计算方法。数值模拟显示了较好的逼近效果。 A photothermal method was proposed to determine the optical and thermal signals related to the surface temperature of the sample by photothermal method. The theoretical treatment and the new effective numerical calculation method were also reconstructed to reflect the depth distribution of the light absorption coefficient in the multi-layered inhomogeneous material. Numerical simulation shows a good approximation effect.