The mandarin duck knife was a sword held by the protagonist Duan Yu in the martial arts novel " Eight Dragons ". It was said that it was forged by the emperor of Dali, Duan Zhengchun, and was worth a fortune. After Duan Yu obtained the mandarin duck saber, he had been able to unleash its astonishing power through continuous cultivation and tempering. The mandarin duck knife was not only a symbol of his identity, but also a symbol of his martial arts. In the novel, Duan Yu and his mandarin duck knife experienced many stories, including the grudges with Murong Fu, Wang Yuyan and others, as well as the life and death struggle with Qiao Feng. The mandarin duck knife became an indispensable part of the novel and one of the readers 'favorite weapons.