Abstract: Aiming at the problem of thickness selection of the layer II waterproof layer and the layer IV air layer of the high temperature working suit，the heat transfer model of three-layer of fabric，air layer，artificial human skin layer was established，the partial differential equation of the model was solved by the finite difference method and the MATLAB mathematical software was used for calculation. The data of temperature distribution were obtained，and a three-dimensional temperature distribution map was generated. Under hypothetical conditions，the optimal thicknesses of layer Ⅱ of waterproof layer and layer Ⅳ of air layer were 19. 06 mm and 5. 78 mm，respectively

Key words: high temperature working clothes, three-layer textile material, heat transfer model, MATLAB, finite difference method, algorithm analysis