Abstract: After 40 years exploration in Biyang depression,the conventional resources of which has been highly prospected,so it becomes more and more difficult to look for big-scaled conventional reserves.With unconventional E&P concept abroad being introduced,the realization of non-darcy seepage flow geological theory innovation on micropores and nanoscale pores,and good breakthrough on drilling completion and multi-stage segmental fracturing technology of horizontal wells,the shale rocks full of rick organic matter become the new exploration target in Biyang depression.The deep sag area of Biyang depression is found to be of the geological conditions for shale oil.Through basic research of shale oil and gas occurrence conditions,the newly drilled BY-HF-1 well achieved commercial flow of high production,making Biyang depression the first area of obtaining shale oil discovery and developing new exploration area for the sustainable development of old oilfield.