Based on the comparison of outcrops and underground depositions of Fal structure in P Oilfield，South Sudan，outcrops of sandy braided-river reservoirs，found in Wuguantun，Datong City of Shanxi Province，were taken as a prototype model to be analyzed in detail through measuring and recording the actual geological profiles. The genetic types and distribution patterns of intercalations were recognized and summarized. On this basis，the impacts of restraining barrier and intercalation on the migration of edge and bottom water in the target area were discussed. The results show that there are five types of intercalations according to the genesis，including channel lag muddy gravel，fine-grained sediments of abandoned channel，fine-grained sediments of flood plain，fallen-silt overlaid mud and lateral accretion mud. Taking one single braided channel as the basic unit，the distribution patterns of intercalations were established，which are characterized as finegrained sediments of abandoned channel superimposed with braided sandbodies，fine-grained sediments of flood plain extending continuously to the outside of the river，fallen-silt overlaid-mud，lateral accretion mud and channel lag muddy gravels filling into the channel sandbodies due to their later erosion and modification. The distribution of fine-grained sediments of flood plain is the main factor preventing edge and bottom water breakthrough according to the distribution patterns of intercalations built for sandy braided-river reservoir in Fal structure，and the blocking effect on edge water becomes serious when intercalations occur with high frequency.