Cyanide containing wastewater mainly comes from electroplating, gas, coking, metallurgy, metal processing, chemical fiber, plastic, pesticide, chemical industry and other departments. Cyanide containing wastewater is a kind of industrial wastewater with high toxicity. It is unstable and easy to decompose in the water. Both inorganic cyanide and organic cyanide are highly toxic substances, which can cause acute poisoning when ingested by people. The lethal dose of cyanide to human body is 0.18, potassium cyanide is 0.12g, and the lethal concentration of cyanide to fish in water is 0.04-0.1mg/l. The main treatment measures for cyanide containing wastewater include: (1) reforming the process to reduce or eliminate the discharged cyanide containing wastewater. If the cyanide free electroplating method is adopted, the industrial wastewater from the electroplating workshop can be eliminated. (2) The waste water with high cyanide content should be recycled, and the waste water with low cyanide content should be purified before discharge. The recovery methods include acid aeration alkali absorption method and steam desorption method. The treatment methods include alkaline chlorination, electrolytic oxidation, pressure hydrolysis, biochemistry, bio iron, ferrous sulfate, air stripping, etc. Among them, basic chlorination method is widely used, ferrous sulfate method is not complete and stable, air stripping method not only pollutes the air, but also does not meet the discharge standard, so it is rarely used.