Artificial photosynthesis of H2O2 from water and oxygen using semiconductor photocatalysts has attracted growing attention because of its green, environmentally friendly, and energy-saving characteristics. Although covalent organic frameworks (COFs) are promising materials for photocatalytic H2O2 production by virtue of their structural and functional diversities, they typically suffer from low charge generation and transfer efficiency as well as rapid charge recombination, which restricts their uses as catalysts for photocatalytic H2O2 production seriously. Herein, we report a strategy for anchoring the vinyl moieties into the skeleton of a COF to facilitate charge separation and migration, thus promoting photocatalytic H2O2 generation. This vinyl group-bearing COF photocatalyst demonstrates a H2O2 production rate of 84.5 µmol h-1 (per 10 mg), which is ten times higher than its analogue without vinyl functionating and superior to most reported COF photocatalysts. Both experimental and theoretical studies have provided deep insights into the origin of the improved photocatalytic performance. Such findings may facilitate the rational design and modification of organic semiconductors for photocatalytic applications.