Firstly, Sb-SnO 2 /potassium titanate (Sb-SnO 2 / KTO) was fabricated by a sol-gel method, it was named ECF. and then Cu 7 S 4 nanorod arrays were grown on the surface of ECF by a hydrothermal method (Cu 7 S 4 NW/ECF).This article discusses the preparation method of Cu 7 S 4 NW/ECF composite photocatalyst to solve the problem of degradation of tetracycline hydrochloride under visible light. It is found that Cu 7 S 4 NW/ECF composite materials can be successfully prepared when Cu : S = 1 : 1, and the Cu 7 S 4 NW/ECF composite has stronger photocatalytic activity then others, The degradation efficiency of tetracycline hydrochloride (TCH) by the composite can reach 98 % after 2 h. which is mainly attributed to the fact that Cu 7 S 4 is a near-infrared material, and a tight heterojunction can be formed between Cu 7 S 4 and ECF, which expands the light response range of the material to a certain extent. At the same time, the direct Z-type mechanism of Cu 7 S 4 NW/ECF composite in the process of photocatalysis is proposed, which is conducive to the separation of electrons and holes. Therefore, the Cu 7 S 4 NW/ECF composite material can effectively degrade tetracycline hydrochloride.