Among the non-contact thermal property measurement techniques, a method utilizing the photothermal effect has been verified for their reliability by many researchers. Among them, the photothermal displacement method, the photothermal deflection method, and the photothermal deflection dollinear method are the most recently proposed thermal property measurement techniques. However, the thermal properties measurement technique previously discussed has various limitations for the measurement, depending on the characteristics of the materials such as absorption and transparency. Therefore, a universal thermal property measurement technique is needed. In this paper, we build a numerical model for reverse photothermal deflection method. In order to validate the numerical model, the grid dependence was verified and the optimum number of grids was obtained. From the comparison of the analytical analysis and the numerical results shows about 0.1% difference each other.