Abstract: A mathematical diffusion model discribing the profiles of concentration and temperature in industrial catalyst particles is given. An effective algorithm based on false transient method to solve the non-isothermal diffusion model is developed. In this paper the numerical solution of the temperature profile and the concentration profile of each reaction component and the numerical solution of effectiveness factor of high-temperature shift reaction catalyst B109 are obtained from 16 groups of experimental data of global rates. The radius of "dead zone" and the effectiveness factor can be directly determined by applying this false transient method and without the need for changing of boundary conditions. The calculated results are reasonable and the calculation is not time consuming.