The CeCoO3/MoS2 heterojunction was successfully prepared through the hydrothermal method. The synthesized heterojunction structure was characterized by various techniques and applied to the conversion of methylene blue (MB) under irradiation of visible light. To characterize the new heterojunction structure, Fourier transformed infrared (FT‐IR), field emission scanning electron microscope (FE‐SEM), energy‐dispersive X‐ray spectroscopy (EDXS), X‐ray diffraction (XRD), photoluminescence spectroscopy (PL), differential reflectance spectroscopy (DRS), and transmission electron microscopy (TEM) analyses were used. The FE‐SEM images illustrated the successful deposition of MoS2 flower‐like on the surface of CeCoO3 perovskite with 46 nm as an average size. The influence of the amount of catalyst, temperature, pH, and electron acceptor were investigated. By CeCoO3/MoS2 heterostructures photocatalyst, the conversion rate of MB reached 98% within 20 min, whereas by CeCoO3 perovskite no significant conversion was observed in MB. The higher photocatalytic performance of CeCoO3/MoS2 heterostructures is assigned to their lower charge recombination compared to CeCoO3 perovskite. Moreover, the photocatalytic mechanism and recycling experiments of CeCoO3/MoS2 heterostructures are discussed in detail. The CeCoO3/MoS2 heterostructures are thus promising photocatalysts for the cleanup of polluted water.