For the problem of high temperature protective clothing design, this paper studies the parameters of the layers of material

to establish heat conduction model based on the law of conservation of energy and Fourier's law, attaining the partial differential

equations with variable coefficients. It uses finite difference method and traversal iterative method to solve the equations, attaining the most suitable convection heat transfer coefficient and temperature change rule, and further getting the optimal thickness and the highest heating temperature. Finally, the model is tested. The deviation from all of the final data is 0.99688, the model results have high accuracy.