Abstract: Jing31-59 is a side-tracked horizontal well, the well depth is 2425 m, and horizontal interval is 2131 m. The position of bell mouth of the hanger is 2126.22 m. Sidetrack drilling dual branch horizontal well in Jing31-59 for making full use of old field. Through accurate design, organization and operation, the net drilling time of the dual horizontal interval in Jing31-59FP is only 15 day, and the accumulated open section length is 768 m. The well is designed and operated by the engineering research institute of Liaohe oil filed, and no experience that can use for reference. The formation of Jing17 block is firm hard, and it is hard to set weight on bit while drilling. The target zone is thin, and the change of the dip angle is significant. It is very difficult to control the well path. By combined with rotary drilling and slide drilling, we regulated the well track by control the drilling parameters. As far as possible prevent the well track rise or drop suddenly, which create better condition for completion. This well is the first sidetrack drilling dual branch horizontal well, and presents abundant experience for sidetrack drilling dual branch horizontal well of other oil field.