According to the requirements of surface microstructural manufacture, the ablation effect of ultrashort pulses on metal materials was studied. By using the double temperature equation, a multi-pulse irradiation analysis model was established. And then the temperature variations rule of single-pulse and multi-pulse ablation metal iron were quantitatively calculated. The results show that some key parameters, such as laser fluence, pulse width, and pulse interval, have noticeably influence on the electron/lattice temperature variation. Finally the number of pulses that needed for the material to reach the ablation threshold under different laser fluence is plotted, which provides a theoretical basis for the laser control in the process.