Promoting the charge separation to improve photocatalytic performance of semiconductor photocatalysts is very important in the field of artificial photosynthesis. Here, we report the synthesis of 2D CdS micro/nano leaves combined with 2D MoS2 nanosheets cocatalyst for efficient photocatalytic H-2 production by visible light via a rapid and cost- effective hydrothermal method. This smart architecture of 2D-2D MoS2/CdS photocatalyst possesses remarkably large 2D nanointerfaces, which provides abundant channels for photoinduced charge transfer between CdS and MoS2. As demonstrated by the photoluminescence and transient photocurrent studies, the large 2D nanointerfaces can efficiently accelerate charge carrier transfer and separation, resulting in the superior photocatalytic performance and favorable stability of MoS2/CdS hybrid photocatalysts for visible-light-driven hydrogen evolution from water. As a consequence, the maximum H-2 evolution rate of 26.32 mmol.h(-1).g(-1) under visible light irradiation and an apparent quantum yield of 46.65% at 450 nm for hydrogen production are achieved on 6% MoS2/CdS, exceeding that of optimized Pt-loaded CdS photocatalyst. The findings indicate that 2D-2D photocatalysts possess great potential for efficient solar hydrogen generation.