Abstract: A new theoretical model has been developed to describe the whole ablation process, including the effect of dynamic absorptance and evaporation. Taking gold as an example, a finite difference method is employed to simulate the electron and lattice temperature evolution under the irradiation of single and multipulse femtosecond laser. The evolution of residual energy coefficient for multipulse as a function of pulse number is given. It is found that the calculated coefficients are in good agreement with the corresponding experimental data, proving the existence of residual energy during femtosecond multipulse ablation.