The mathematical models for the number of branches of the thin layer fish bones well, the branch borehole length, branch angle and distance between the branch borehole system optimization model have been established. Some key issues such as safe separation between the main borehole and the branch borehole, Interlayer wall construction method of the unconsolidated strata, drilling string and completion string trip-in have been solved. A suit of technology such as open hole sidetracking technology, Interlayer wall construction method of the unconsolidated strata and drilling string and completion string trip-in technology have been formed. Through integrated application of geological-oriented drilling, composite drilling, trajectory control, open hole sidetracking technique and other supporting technologies, have completed two wells on-site testing. Technical problems such as go across the ultra-thin oil layer, branched hole three dimensional Pressurize and evaluation of drilling tool throughput capacity have been solved successfully. We achieved in drilling branch in 1.5 m thickness of the reservoir. It is currently the thinnest oil drilling fishbone wells. The early production of the two test fish bone wells has reached 10 times to the conterminous well, stable output is 3.5 times, Its effect is significant. Fishbone well Technology put the Single path horizontal section plane extends to more than one horizontal wellbore. Achieved more expose reservoir and increased the well production, providing an effective approach for economic development of low permeability, low abundance and thin low-yielding oil field reservoir.