Deng Fei was from Xiangyangfu, Huguang. He had a pair of fiery-red eyes thus earning the nickname 'Fiery eyed Suan-Ni' (火眼狻猊). He used a long iron chain in battle.
Deng Fei was Yang Lin's friend, and once Yang Lin and Dai Zong passed by Yinma River, they met Deng Fei and his gang, then became fast friends. Deng Fei, along with Pei Xuan and Meng Kang disguised themselves as government soldiers, then to join the Liangshan band.
Deng Fei became one of the leaders of the Liangshan cavalry and 72 Earthly Fiends. After Song Jiang had obtained amnesty from the emperor, Deng Fei followed the heroes on their campaigns against the Liao Tartars and southern rebels, making great contributions. During the Fang La campaign, Deng Fei followed Lu Junyi to attack Dusong Pass. Lu sent Deng Fei, Ou Peng, Li Zhong and Zhou Tong as scouts to find out about the land around the pass. Suddenly, the enemy troops charged out of the pass and killed Zhou Tong when he was not looking. Deng Fei and the others managed to escape in time.