The invention discloses a flexible formation device for a thin-walled ripple disc and a method using the flexible formation device to manufacture the thin-walled ripple disc, and aims to solve the difficult problems that a conventional thin-walled ripple disc is low in forming limit and high in probability of cracking. The flexible formation device comprises an upper die, a lower die, a filling chamber, a liquid inlet channel and a connector, wherein a groove matched with the shape of the ripple disc is formed in the profile of the lower die, and the connector connected with a high-energy-rate filling device and the liquid inlet channel of a high-pressure liquid are also arranged to form a closed high-pressure liquid chamber. The invention also provides the flexible formation method which uses the flexible formation device to manufacture the thin-walled ripple disc, and a step-by-step progressive high-energy-rate impacting and filling compound forming method is adopted to improve the forming limit of a material. The method provided by the invention belongs to dynamic energy formation and has the advantages of high energy, speed and efficiency. A product produced by the method is high in forming precision and low in production cost and can form various plate parts with complicated features.