During the Tang Dynasty, there was war at the border. Li Haobai, a young man from Shu, had his country and the world in his heart. In order to realize his ambition, he and his friend Hu Jian embarked on a journey to Hangu Pass to join the army. In troubled times, evil spirits appeared. In the city of Chengdu, the old Taoist Xiaoyaozi went around to exorcise demons. Far away in Chang'an, the old Taoist Xun Guoshi, who had bad intentions, deceived the emperor to cultivate immortality and used his minions to wantonly capture "dragon beasts" to cultivate immortal pills. By chance, Li Haobai merged with the "Lizhu" in the dragon beast's body, and for a time he became the target of public criticism. Not only did Xun Guoshi's men want to capture Li Haobai, but people from all walks of life in the rivers and lakes also wanted to obtain the Lizhu to cultivate immortality. Li Haobai was rescued in danger by Xiaoyaozi, who passed by to exorcise demons. Xiaoyaozi warned Li Haobai that if he did not take out the Lizhu and return it to the dragon vein of heaven and earth, Li Haobai would explode and die within 30 days, and the world would also suffer a catastrophe due to the turmoil of the dragon vein. He and his friend Hu Jian went to Hangu Pass to join the army. On the way, they met Ayimu, a wandering girl from the Western Regions. The three of them got along well and went to Hangu Pass together. In order to protect Lizhu, Xiaoyaozi had to follow them all the way and act according to circumstances. Along the way, the four escaped from the pursuit of Xun Guoshi many times. During this period, Lizhu gradually merged with Li Haobai, and Li Haobai accidentally transformed into a "black dragon". During the journey, the white dragon symbolizing "yang" suddenly appeared and entangled Li Haobai all the way. The mysterious white dragon led Xiaoyaozi to leave Li Haobai and track down the white dragon to explore the secret. The appearance of Lizhu spread all over the world, and Li Haobai, who was carrying Lizhu, attracted the pursuit of strange people in the world.