BiFeO3 is a photocatalyst with excellent performance. However, its applications are limited due to its wide bandgap. In this paper, MIL-101(Fe)@BiOI composite material is synthesized by hydrothermal method and then calcined at high temperature to obtain BiFeO3@Bi5O7I composite material with high adsorption capacity. Among them, An n-n heterojunction is formed, which improves the efficiency of charge transfer, and the recombination of photo-generated electrons and holes prevents the improvement of photocatalytic efficiency and stability. The result of photocatalytic degradation of tetracycline under visible light irradiation showed, BiFeO3@Bi5O7I (1:2) has the best photodegradation effect, with a removal rate of 86.4%, which proves its potential as a photocatalytic degradation material.