This work reports on the synthesis and characterization of a series of Schiff-base cobalt(Ⅲ) complexes 1～4 that exhibit an obvious catalytic activity for hydrogen production in aqueous solution using fluorescein (FL) and triethanolamine (TEOA) as photosensitizer and electron donor, respectively. The complexes display the capability of splitting of water for H₂ evolution. Under optimized conditions, complex 3 shows better properties for photocatalysis, 25 mg of which can release 152.3 μmol of H₂ after irradiation for 3 h. The mechanism for light-driven H₂ production was explored by experiments and density functional theory (DFT). Meanwhile, the reason of releasing hydrogen was explained theoretically in detail. The research results will help to understand the interaction of cobalt complexes with the photosensitizer and design new photocatalysis for the future.