For a TbFeCo quadrilayer illuminated by laser beam,absorption of the laser power within different layers was considered by analysizing the rate of absorption of energy per unit volume.With the help of implicit method,the profile of temperature of the multilayer was given and the diffusion of heat was studied.The effect of laser power,laser duration and the convection loss at the front surface upon the thermal characteristics of the multilayer was investigated.This thermal analysis procedure provided a good example for the thermal investigation within other optical disk systems.