Li Huai (Liu Kaiwei) is the grandson of Li Xunhuan, a great hero in the martial arts world. One day, he was involved in a theft of official silver by mistake, and was seriously injured and in danger of death. Fortunately, Li Huai's childhood sweetheart Fang Keke (Wu Yingjie) rescued him in time, and the former was spared. After that, Li Huai met a chivalrous woman named Xue Caiyue (Yang Rong), and the two developed feelings for each other. Li Huai inherited the secret book of Xiao Li Feidao from his father, so he became the target of the court and the martial arts world. Among them, Gao Gonggong, the supervisor of the East Factory, repeatedly tried to kill Li Huai. Fang Keke, who had a crush on Li Huai, began to investigate Xue Caiyue's true identity, and was shocked to learn that she was the first killer in the martial arts world, "Moon God", who had failed to assassinate Li Huai. But in fact, Xue Caiyue had already fallen in love with the upright and brave Li Huai, and she was pregnant with Li Huai's flesh and blood.