Abstract: Large frictional torque, backpressure during slide drilling, low rate of penetration (ROP), poor recognition of reservoirs by geosteering, and other problems are encountered during the drilling of large-cluster horizontal shale oil wells in the Changqing Oilfield. In this regard, this paper studied the multi-layer layout of large-cluster horizontal wells, large offset design, three-dimensional well trajectory control technology, and drilling tools for ROP improvement. Technical breakthroughs were made in the optimized deployment of well patterns/sequences, the anti-collision design between dense well group trajectories, the completion of horizontal well in one trip, the evaluation and accurate control of reservoirs while drilling, and the safe drilling in water injection areas,etc. Finally, the ROP improvement technologies for large-cluster horizontal shale oil wells in the Changqing Oilfield were developed. The field tests of the technologies were carried out in large-cluster well platforms, the Platform Hua H40 and the Platform Hua H60. The maximum number of horizontal wells in the well clusters was 22, with an average drilling cycle of 18.9 d, which was shortened by 7.5% after using the technologies. The research and field application demonstrate that the ROP improvement technologies for large-cluster horizontal wells have realized the large-scale development of shale oil in the Changqing Oilfield, promoting the construction of the Longdong National Shale Oil Demonstration Base.