Oil of the Fuyu and Yangdachengzi oil layers (F—Y oil layers ) in the Shangjia oil field, Songliao basin, is mainly from the 1st Member, Qingshankou Formation, Lower Cretaceous(K2qn1) source rock in the Sanzhao depression. The Fuyu and Yangdachengzi oil layers are the results that oil generated from K2qn1 source rock migrated downward to F—Y oil layers through T2 source faults and then migrated laterally through sand body passages connected by faults. According to the characteristic that oil—water distribution relation of F—Y oil layers in the Shangjia oil field is complicated and oil accumulation and distribution process is mainly controlled by active faults, faults of Shangjia area in main hydrocarbon generation and expulsion stages of source rock are divided into inherited active faults and occlude faults that are nonactive, and lateral transportation mode of reservoir sandstone in two walls of fault controlled by active faults is established. It is showed that oil which migrated laterally into F—Y oil layers in the Shangjia oil field was controlled by sand—sand juxtaposition in two walls of fault in the control of active faults. In the process of migration, oil migrated in occlude fault traps and fault—lithology traps which were encountered. And then the migration process ceased. This migration mode allows oil accumulating in the high part of structure complicatedly and randomly. These features become obvious when oil source area is far away. And the distribution strata of oil in the longitudinal direction are enlarged. Oil is injected and accumulated in upper strata of fault block near oil source area, which is normal oil—water system that is oil upper—water lower. Oil and gas can also enrich in lower strata of fault block far away from oil source area, and then there are two or many sets of oil—water systems, where oil—water distributions are complex. The accumulation period of oil and gas in traps far away from oil source area is earlier than that in traps near oil source area. In the same fault block, oil accumulation period of upper strata is earlier than that of lower strata.