Abstract: Prestack deep migration (PDM) as the best way to solve the accurate imaging of complex structures in Kuqa mountain land requires high precision in velocity, so the imaging quality of PDM is normally unsatisfactory in the condition of an inaccurate velocity model and low S/N. It is indispensable for using prestack time migration (PTM) data to guide the structural understandings in this area. The key point of Kirchhoff prestack time migration technology applied to Kuqa mountain land is the estimation of seismic travel time and the accurate solution of root-mean-square velocity on the relief surface. The former includes calculation of the time t0 of each imaging point and the travel time of shot-to-geophone points in the imaging point’s gather from the near-surface, and the latter includes the fine velocity analysis and the velocity scanning. By using this method, good imaging effects are obtained in actual seismic data processing from Kuqa mountain land, and worth further researching and generalizing.

Key words: Kuqa mountain land, relief surface, travel time estimation, root-mean-square velocity, prestack time migration