Photocatalytic covalent organic frameworks (COFs) are popular in the field of biomedical materials and also have potential as antimicrobial materials. Herein, a boron-based COF was used in antibacterial applications innovatively. The results of this study suggested that COF-1, the earliest boroxine COF, could produce a variety of reactive oxygen species (ROS) under visible light irradiation. In order to explore more applications of COF-1, antibacterial tests were carried out based on the above results. The test results showed that the material displayed an obvious bactericidal effect on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) by releasing ROS under white light. According to the results of plate coating, all bacteria died after co-cultivation with COF-1 under white light for about 120 minutes. In a word, this study could provide a new idea for the application of boron-based COFs as multifunctional photocatalysts in future.