Abstract: Horizontal well drilling in Yuanba area had characteristics of big construction difficulty,high risk and high level of security development requirements.Trajectory control technique was an important part in overall horizontal drilling techniques.Through analyzing the difficulties of horizontal well drilling in Yuanba area,the drilling tools,instruments,bottom hole assembly and drilling parameters were analyzed and optimized firstly.And then,based on construction requirements,the technical proposal of specific trajectory control technique was put forward,which mainly included deep sidetracking technique,trajectory control technique in deflecting section,ultra-deep landing control technique and trajectory control technology in horizontal section.On this basis,the measuring instrument suitable for ultra-deep horizontal wells under high temperature and high pressure was optimized and the operational procedures were formed,which could improve the drilling efficiency.