Photocatalytic water splitting into H2 is the most economic and environmentally friendly strategy for H2 production, and rationally constructing a heterojunction retains enormous influence on a photocatalytic system. Herein, 2D/2D covalent organic framework/graphitic carbon nitride (COF/CN) van der Waals heterojunctions were readily prepared via an ultrasonic method for high-efficiency visible-light photocatalytic H2 production. The photocatalytic H2 production performance of optimized COF/CN composites can reach up to 449.64 μmol·h-1, which is approximately 5 times that of pure CN (89.08 μmol·h-1). The characterization and experimental studies reveal that the synergistic effect between COF and CN contributes to promoting the interfacial migration and spatial separation of photoinduced e--h+ pairs, further boosting the photocatalytic hydrogen production activity. This work may open a new window to design and fabricate effective heterojunction photocatalysts for photocatalytic energy conversion.