Solar-driven production of chemical fuels through photocatalysis holds great promise for addressing the ever-increasing energy and environmental issues. However, its practical application is limited due to low light harvesting efficiency, fast charge recombination, and low stability of current photocatalysts. Here, we introduce a high-performance solar energy conversion platform constructed by the intimate coupling of two different complementary semiconductors (MoS2 and CdS) and morphology-controlled plasmonic metal nanocrystals (concave cubic Au nanocrystals) in a controlled manner. The sequential Au nanocrystal anchoring and CdS growth on two-dimensional exfoliated MoS2 nanosheets successfully yielded intimately coupled plasmonic metal-semiconductor ternary hybrids. The prepared hybrid photocatalysts exhibited superb hydrogen evolution capability under visible-light irradiation, which can be attributed to the synergistic integration of the advantages of semiconductor-semiconductor coupling, such as the broadening of light absorption and the retardation of charge recombination, and plasmon energy transfer from Au nanocrystals to semiconductors via the hot electron transfer mechanism.