According to the geological engineering difficulties in AT9 well area and the special requirement of anti-bumping in the straight section of cluster wells, the designs of well location, platform layout, borehole trajectory and well structure are optimized. The paper introduces the key techniques of MWD anti-bumping, PDC straight spiral rod composite drilling and drilling fluid in drilling process, analyzes the technical rationality and the development economy of cluster well group and verifies the applicability of the cluster drilling technology in AT9 well area.