The treatment of cyanide in waste water of coke-oven plant with radiation-technique was investigated. The investigation indicated that toxic products. under γ-ray irradiation were changed into less-toxic or non-toxic products. Organic pollutants will compete with cyanide for scavenging active intermediates of water (H,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649972&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649974&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649973&type=, and OH radical). Therefore, it will inhibit cyanide radiolysis. The pretreatment with active carbon increases the radiolytic decomposition rate of cyanide and damage rate of organism in waste water. H,2,O,2, and N,2,O convert ,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649975&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649977&type=,http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=42649976&type=, into OH radical. however they improve the efficiency decomposition of cyanide. OH radical plays an important role in reducing cyanide content and COD value.