Ultra-fast laser technology is now widely used in the processing of micro and nano structures.The extremely small size produces heat transfer characteristics different from macroscopic conditions and it has gradually become a research focus.An improved dual-phase-lagging (DPL) model is utilized to investigate the two-dimensional thermal conduction of nano-silicon films irradiated by ultra-fast laser.The modified DPL equation reflecting the size effect is solved by integral variation method.The variation of the internal temperature along the thickness direction and the radial direction of the thin film is analyzed.The result shows the temperature increases rapidly in the heated region of the film,and the energy is gradually transferred to the inside of the film in the form of waves.Although both the results based on the improved DPL model and the DPL model can obtain similar thermal wave temperature fields,the temperature distribution in the film obtained by the improved DPL model is relatively flat.Under the same Knudsen number,the temperature obtained by the two-dimensional improved DPL model is higher than that obtained by the one-dimensional model,and the temperature difference becomes larger and larger as time goes by,which implies that the radial heat conduction has an important effect on the temperature distribution inside the film in the two-dimensional heat transfer process.