Due to unique structure and properties of MOFs, a well-designed functional CdS/ZIF-67 composite photocatalyst was successfully synthesized by hydrothermal synthesis to achieve efficient hydrogen evolution. The obtained composite photocatalyst can not only make use of the specific surface area of ZIF-67 to provide a larger reaction place, but also can positively promote the reaction by binding sites between CdS and ZIF-67. Under visible light (5 W LED white light) irradiation, the maximum amount of hydrogen evolution reached 308 mol in 5 h which was about 50 times higher than that of pure ZIF-67. The composite photocatalyst exhibited a significantly stronger stability than single component. The in-depth study of binding sites by electrochemical experiments showed that the photocurrent of the photocatalyst has increased to 1.8 mu A cm(-3), which showed that the existence of binding sites could effectively improve the electron transfer rate. And the synergy between them also can promote the separation of electron-holes and reduce the recombination rate. Therefore, reaction mechanism was proposed from the view of electron transfer for deep understanding. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.