Ultraviolet-C （UV-C） irradiation can effectively deactivate pathogenic microorganisms. The far UV-C （200-230 nm） and conventional UV-C （250-280 nm） can damage the proteins and nucleic acids of pathogenic microorganisms, respectively. The combination of far and conventional UV-C has the potential of synergistic inactivation. However, relevant studies remain limited owing to the lack of appropriate experimental setups. Therefore, this study established a mini-fluidic photoreaction system equipped with a KrCl excimer lamp and a low-pressure mercury lamp. This system could independently/simultaneously deliver stable 222 nm （far UV-C） and 254 nm （conventional UV-C） irradiations. Subsequently, the system was used to investigate the synergistic effect of dual-wavelength UV-C （the combination of 222 nm and 254 nm UV-C） on