Discovered in 1939, the traditional anthraquinone method has been utilized to manufacture over 95% of the valuable chemical hydrogen peroxide (H2O2) industrially, resulting in high energy consumption and the generation of hazardous secondary by-products. Calling for the photocatalysis processes, it has been demonstrated that the sluggish kinetics of the oxygen reduction reaction (ORR), water oxidation reaction (WOR), and severe electron-hole pairs recombination make the non-sacrificial H2O2 photoproduction challenging. To overcome these challenges, covalent organic frameworks (COFs), a well-known carbon-based material, have been considered one of the most powerful photocatalytic feedstocks for non-sacrificial H2O2 photosynthesis, especially in natural seawater. Herein, we summarize the recent advances made in COF catalysts, preparation strategies, and their application for H2O2 photosynthesis in pure water and natural seawater. The relevant content of theoretical simulations, structural characterizations, future prospects, and limitations is also discussed elaborately and critically. We anticipate that this review will furnish insight into current progress and inspire the progress of next-generation photocatalytic materials for sustainable and non-sacrificial H2O2 photoproduction, especially in seawater as a natural source. © 2026 Elsevier B.V.