After washing his hands, Hu Bayi helped his friend Uncle Ming go to the South China Sea to salvage the pearls. Unexpectedly, he encountered a shipwreck and fell to the bottom of the sea, but accidentally found a thousand-year-old ruins of an ancient country that sank at the bottom of the sea. They went through many hardships and dangers at the bottom of the sea, and finally united to defeat the deep-sea beasts, and cleverly used the equipment in the ruins to escape.