Modifying g-C3N4 with covalent organic frameworks (COFs) through imine linkage results in a dramatically enhanced visible-light-driven photocatalytic hydrogen evolution, which reached 10.1 mmol g-1 h-1 when 2 wt% Pt and triethanolamine were used as co-catalyst and sacrificial agent, respectively, corresponding to an apparent quantum efficiency (AQE) of 20.7% at 425 nm.