Abstract: In order to solve the technical difficulties such as low ROP, long drilling cycle and high downhole risks of shale gas horizontal wells with ultra-long horizontal section in the Changning Block, with theoretical analysis and software simulation calculations, the well trajectory was optimized, the proper drilling equipment and casing running methods were selected, and technical measures were taken to reduce downhole risks, such as introducing vibration reduction and acceleration, leak prevention and plugging. These technologies were developed to form a key technology for the safe and efficient drilling and completion of shale gas horizontal wells with ultra-long horizontal sections in Changning Block. The technology had been tested in 3 horizontal wells with ultra-long horizontal section in Changning Block, no downhole failure occurred during drilling and completion, while ROP was increased by 2.5% and drilling cycle was shortened by 16.9% compared with the offset wells. This showed that this technology could solve the challenges in drilling and completion of those shale gas horizontal wells with ultra-long horizontal section in Chang-ning Block, ensure the safe and efficient drilling and completion in Changning Block, and could be popularized in this block.