MBT can kill the main bacteria, fungi and algae (all kinds of fungi) in circulating water with high efficiency, long duration and wide range of PH value and temperature. The sterilization rate of heterotrophic bacteria, nitrite bacteria, sulfate reducing bacteria, Escherichia coli, iron wire bacteria, anaerobic bacteria, denitrifying bacteria and sulfur bacteria is as high as 99%, and it can also achieve high sterilization rate for other kinds of bacteria. Dithiocyanatomethane is more effective than other killing/disinfection drugs in removing various fungi. Its stock solution is stable, can be quickly degraded/decomposed when used, does not cause secondary pollution to the environment, has high efficiency and low residue, and is harmless to human body/livestock. Safe discharge can be realized. It is the best broad-spectrum algaecide/bactericidal drug at present.