Abstract: Using the variable-separated method，the exact solution of relationship between temperature and time inside a finite length energized cylinder under the second kind and third kind boundary conditions is obtained， and through the simulation by COMSOL multi-physics software of computers，the distribution diagrams of temperature inside the cylinder are also presented. It is found that the simulation results of the surface temperature and inner temperature of the cylinder are corresponded with the experiment values，the maximum temperature of the simulation results and experiments are almost the same，which agree with the prediction of the analytic solutions.

Key words: finite length energized cylinder, temperature field, variable-separated method, Bessel function, COMSOL