Abstract: With the in-depth geological study in the Yinggehai and Qiongdongnan Basin, it is required to improve the quality of seismic data for deep strata (under-2 700 m). Enhancing S/N ratio for images is one of the choises. The technique of common reflection surface stacking (CRS) has a lot of advantages. It takes not only partial characteristics but also all the reflections in the Fresnel zone into account. CRS stack has good adaptability to a complex geological situation. It can achieve real high S/N ratio stacking for better imaging in the deep layer. The article combines the theoretical analysis, model testing and seismic data processing together. S/N ratio and interpretation reliability are improved for deep seismic data. In this regard, CRS stacking is worthy to be promoted in the Yinggehai and Qiongdongnan Basin.