Deep-water submarine fans are important depositional sinks in source-to-sink systems, yet the multi-tier coupling relationships and sandbody redistribution processes under bottom-current influence remain insufficiently understood. This study focuses on the Upper Huangliu Formation in the Yinggehai Basin. By integrating seismic profiles and attributes, core-based sedimentological observations, heavy-mineral assemblages, lithic compositions, and detrital zircon U–Pb age data, and regional geological constraints, we investigate the multi-tier source-to-sink system and the role of bottom-current reworking in the study area. The results reveal a three-tier coupled source-to-sink framework in the study area, comprising: (i) source area to shallow-water delta (Tier 1), (ii) shallow-water delta to deep-water submarine fan (Tier 2), and (iii) bottom-current reworking and redistribution superimposed on submarine-fan deposits (Tier 3). At the Tier-1 level, multiple zoned depositional belts are developed in the basin-margin shallow-water area, and sediments derived from different source directions show distinguishable compositional responses in the shallow-water setting. At the Tier-2 level, seismic geometry and depositional-system distribution indicate that different shallow-water deltas transported sediment basinward along slope-break zones and formed submarine fans with clear geometric correspondence on slopes and in depressions; most sample points are mainly controlled by a single shallow-water provenance end-member, whereas depocentral areas display stronger compositional complexity. At the Tier-3 level, erosional–lateral accretion observed on seismic profiles, together with sedimentary structures in cores, indicate that bottom currents reworked and redistributed pre-existing submarine-fan sand bodies, causing some sand bodies to become elongated along the prevailing flow direction in plan view and to undergo architectural reorganization. On this basis, we propose a multi-tier conceptual source-to-sink model of “source area–shallow-water delta–deep-water submarine fan–bottom-current redistribution.” This model emphasizes that, in marginal basins jointly controlled by slope-break architecture and bottom currents, submarine fans do not necessarily represent the final depositional endpoint, and important post-fan redistribution processes may still occur, thereby influencing the spatial distribution and compositional characteristics of deep-water sand bodies. This framework provides important implications for constraining the genesis of deep-water sand bodies and improving the prediction of favorable reservoirs.