The invention relates to a treating method for removing three kinds of dioxin-like compounds in waste incineration waste off gas. The method comprises the steps that waste incineration waste off gas is introduced into a sufficient treating agent through a pipeline, 2,3,7,8-tetrachlorodibenzo-p-dioxin, 1,2,3,7,8-pentachlorodibenzo-p-dioxin, and 1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin in the off gas react with the treating agent, and complex precipitate is formed and filtered out. The treating agent is formed by compounding terpinyl acetate, n-butyllithium, 2-amino-3,5-dibromopyrazine, 2-amino butane, 4-(4-hydroxy-3-methoxyphenyl)butan-2-one, 4-acetoxyl group-3-methoxy-(2-propenyl) benzene, 2-methylpiperazine, 6-methyl chromene, 3alpha,12alpha-dihydroxy-5beta-cholanic acid and the like. The treating agent has the strong complexing power with target matter, the complex precipitate forming speed is high, the removing rate can reach 99%, the cost is low, consumption is small, the application range is wide, and no damage is produced to the environment.