The borehole WFSD-4S of Wenchuan earthquake fault scientific drilling project is a shallow supplemented hole through Wenchuan earthquake main slip band for further understanding the main slip of the Wenchuan earthquake to get more comprehensive drilling data, which is located near the surface rupture zone by the fourth hole in the Nanba region. The paper introduces the key technology and measures applied in the borehole WFSD-4S of Wenchuan earthquake fault scientific drilling project for the difficulties of complex geological conditions and low core recovery. The results of its application were analyzed and summarized; the detailed discussion was made on the formation conditions, the construction process, coring drilling tools, drilling fluid technology and accident treatment, which will provide important reference for the selection of reasonable coring technology in future complex formation drilling.