Abstract: How to improve the obscure-zone images is a very difficult problem in seismic exploration in Yinggehai basin. In order to resolve this problem, multi-wave seismic data were acquired in 1998 in the area. Through P-SV wave processing, good imaging was achieved in obscure zone. On the basis of analysis on special problems, in migration of processing P-SV waves, a new prestack migration technique for P-SV waves was put forward. This technique sorted raw data into common converted scattering points to form CCSP gather. In the CCSP gather, two-way travel time and equivalent offset accord with hyperbola relationship, so Kirchhoff prestack time migration used to conventional P-P wave can be applied to it. Velocity analysis can also be processed by P-P wave method. Therefore this technique simplifies P-SV processing flow and improves P-SV image result.