To fulfill photocatalytic H₂ production under visible light irradiation, (CuAg)_xIn_2xZn2(1-2x)S₂ photocatalysts were synthesized using the precipitation and calcination. X-ray diffraction (XRD), ultraviolet-visible absorption spectra (UV-Vis), dynamic light scattering (DLS), energy-dispersive X-ray spectroscopy (EDS), and inductively coupled plasma mass spectrometry (ICP-MS) were employed to investigate band structures of the photocatalysts and evaluate photocatalytic activities. The results show that the absorption edges shift to longer wavelengths up to visible-light region and band gaps decrease with the increase of x. In addition, the conduction band potentials are close to the redox potential of H+／H₂ with the increase of x. The prepared (CuAg)_xIn_2xZn2(1-2x)S₂ (x=0.05-0.30) photocatalysts exhibit the activities of H₂ production under visible light irradiation, and (CuAg)0.15In0.3Zn1.4S₂(x=0.15) shows the highest photocatalytic activity. The band structures of (CuAg)_xIn_2xZn2(1-2x)S₂ were manipulated by adjusting the composition ratio, which will help design visible-light-response photocatalysts with the high activity and stability.