Abstract: In order to solve the defects in the structure and performance of single-phase photocatalytic materials, the 2D graphitic carbon nitride (g-C₃N₄) was synthesized by secondary calcining, and Ag/g-C₃N₄ was prepared via photodeposition method. SnS₂-Ag/g-C₃N₄ with n-n type heterojunction structure was prepared through simple ultrasonic and solvent evaporation methods. The microstructure, phase structure, light response ability and pore structure of the materials were characterized. The results showed that the lamellar structure and the spray shape coexist in the composite. The 2D-0D-2D morphology similar to sandwich structure is formed. The composite has high crystallinity and well-constructed interface, which give it a higher specific surface area and stronger visible light response performance. When the mass fraction of SnS₂ is 10wt%, the photocatalytic degradation efficiency of the SnS₂-Ag/g-C₃N₄ composite is up to 95.6%, and the degradation rate is 3.5 times as that of g-C₃N₄. After 4 cycles, the photocatalytic efficiency remained above 85.3%.