The synthesized g-C₃N₄/MoS₂ composite was a high-efficiency photocatalytic for hypophosphite oxidation. In this work, a stable and cheap g-C₃N₄ worked as the chelating agent and combined with the MoS₂ materials. The structures of the fabricated g-C₃N₄/MoS₂ photocatalyst were characterized by some methods including X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectra (XPS). Moreover, the photocatalytic performances of various photocatalysts were measured by analyzing the oxidation efficiency of hypophosphite under visible light irradiation and the oxidation efficiency of hypophosphite using the g-C₃N₄/MoS₂ photocatalyst which was 93.45%. According to the results, the g-C₃N₄/MoS₂ composite showed a promising photocatalytic performance for hypophosphite oxidation. The improved photocatalytic performance for hypophosphite oxidation was due to the effective charge separation analyzed by the photoluminescence (PL) emission spectra. The transient photocurrent response measurement indicated that the g-C₃N₄/MoS₂ composites (2.5 μA cm^–2) were 10 times improved photocurrent intensity and 2 times improved photocurrent intensity comparing with the pure g-C₃N₄ (0.25 μA cm^–2) and MoS₂ (1.25 μA cm^–2), respectively. The photocatalytic mechanism of hypophosphite oxidation was analyzed by adding some scavengers, and the recycle experiments indicated that the g-C₃N₄/MoS₂ composite had a good stability.