The embodiment of the invention provides a method and a device for modeling the near-surface speed. The method comprises the steps of obtaining the near-earth surface inversion speed model of a targetnear-surface, and the static correction amounts of a shot point and a wave detection point; determining the surface elevation smooth surface of the target near-surface, and determining the surface elevation smooth surface as an offset reference plane; determining the travel time of the shot point and the wave detection point from a high-speed top interface to the surface elevation smooth surface;updating the static correction amounts according to the travel time; correcting CMP trace gather data according to the updated static correction amounts and obtaining CMP trace gather data before offset; correcting the CMP trace gather data before offset to the offset reference plane; and obtaining a superficial layer speed model according to the near-earth surface inversion speed model and the CMP trace gather data before offset and corrected to the offset reference plane. According to the embodiment of the invention, the modeling precision and the pre-stack depth offset imaging precision can be improved.