Abstract: Dushanzi area in the southern margin of Junggar basin is characterized by complex near?surface structure, up?steep and down?gentle geological structure style, fault development and very complicated wave fields, which give rise to difficulties in the pre?stack depth migration in this area. This paper presents the key procedures for the seismic pre?stack depth migration velocity model (PSDM) applied in Dushanzi area: (1) making full use of well data to establish interval velocity map, and eliminate the influence of near?surface Xiyu conglomerate on the underlying interval velocity; (2) making restricted correction of the seismic velocity using drilled well velocity data and improving the accuracy of the velocity model with along?layer coherent inversion; (3) establishing the 3D velocity model based on the 2D grid to ensure the closure of space and time in 2D grid velocity field. The case study shows good imaging effects by using the PSDM technology