The protagonist, Yang Guo, is the orphaned son of Yang Kang, the antagonist in The Legend of the Condor Heroes. The couple Guo Jing and Huang Rong take Yang Guo under their care for a short period of time before sending him to the Quanzhen Sect on Mount Zhongnan for better guidance in moral values and orthodox martial arts.
In Quanzhen, Yang Guo is often bullied by his fellow students, and discriminated against by his master, Zhao Zhijing. Yang Guo flees from Quanzhen and ventures unknowingly into the nearby Tomb of the Living Dead, where the Ancient Tomb Sect is housed. He is saved by Xiaolongnü, a mysterious maiden of unknown origin, and becomes her apprentice. They live together in the tomb for many years until Yang Guo grows up.
Yang Guo and Xiaolongnü develop romantic feelings for each other, but their romance is forbidden by the prevailing norms of the jianghu (or wulin, the community of martial artists). Throughout the story, their love meets with several trials, such as the misunderstandings that threaten to tear them apart, and their encounter with Gongsun Zhi, whom Xiaolongnü almost marries at one point.
Finally, after their reunion and marriage, Xiaolongnü leaves Yang Guo again, owing to her belief she cannot recover from a fatal poison, and promises to meet him again 16 years later. While Yang Guo is wandering the jianghu alone, he meets several formidable martial artists and a giant condor, and improves his skills tremendously after training from them. His adventures gradually mould him into a courageous hero and the most powerful martial artist of his time.
Yang Guo serves his native land by helping the Han Chinese people of the Song Empire resist invaders from the Mongol Empire. At the end of the novel, he is reunited with Xiaolongnü and they leave to lead the rest of their lives in seclusion after receiving praises and blessings from the wulin.
Michelle Chen as Xiaolongnu
Xiao Chen as Yang Guo
Mingna Yang as Huang Rong
Xinyu Zhang as Li Mochou
Guolin Zheng as Guo Jing