The difficulty in immobilizing carbon nitride (GCN), and the decrease in sorption capacity and photocatalytic performance after immobilization process have become two major bottlenecks limiting the practical application of carbon nitride in photocatalysis field. Herein, sulfur doped carbon nitride and carbon nanotube composite photocatalysts (CNT/SCN) with high sorption, light harvesting capacity, and reduction efficiency was synthesized by two-step solvothermal method. Furthermore, CNT/SCN composite photocatalytic coating with porous three-dimensional surface morphology was prepared using double liquid phase high speeding spray-deposition method. The coverage rate of CNT/SCN coating was calculated to be 55 %, which was 1.57 times higher than that of GCN coating. The introduction of carbon nanotube (CNT) significantly improved the sorption capacity of photocatalytic coating for hexavalent chromium (Cr6+(aq.)). The reduction efficiency of the composite coating towards Cr6+(aq.) under flowing water conditions was further investigated. The CNT/SCN coating exhibited a high removal efficiency of 84.7 % for Cr6+(aq.) (500 mL, 10 mgL−1) within 8 h, which was 29 times than that of GCN coating. The reduction efficiency of CNT/SCN photocatalytic coating remained above 75 % after three cycles of testing. This research provides theoretical basis and data support for the immobilization application of photocatalysts.