The utility model relates to a dual-coupling and overlapping gating system used for the molding of a large thin-wall die-casting, which comprises a sprue bushing, a moving die insert, a fixed die insert, a side core, a sprue spreader, ingates, a transversal gate runner, and a straight gate runner. The gating system is characterized in that one ingate is arranged on each of the two side walls of the thin-wall casting; the ingates on the two sides are connected by a dual-coupling and overlapping structure and connected with the transversal gate runner; and after being injecting into the transversal gate runner, the liquid alloy is shunted to the ingates on the two sides and flows into a molding cavity through the dual-coupling and overlapping structure. The flow path of the liquid alloy is short, thereby avoiding the phenomena of coldshut or undesirable fusion welding; when the molding cavity is filled with the alloy backfills, the backfilling materials are balanced, and the flow state of the feeding from single side is totally changed; pressuring and feeding effects are good, shrinkage of the products is small and uniform, and the internal stress is low; in addition, the overlapping part plays a supporting role in the cooling shrinkage, so that the probability of the product buckling deformation is reduced, the spacing between the two side walls changes very little, the product quality is greatly improved, and the time to backfill the cavity is shortened. Therefore, the gating system is an ideal novel gating system for a thin-wall die-casting mold.