Bead-in-bead preparation as well as preparation device and preparation method thereof

The invention provides a bead-in-bead preparation as well as a preparation device and a preparation method thereof. The bead-in-bead comprises a large dropping pill, a first small dropping pill and a second small dropping pill, the first small dropping pill comprises a first formula combination and a first shell layer wrapping the first formula combination, and the second small dropping pill comprises a second formula combination and a second shell layer wrapping the second formula combination. The large dropping pill comprises a third formula combination and a third shell layer wrapping the third formula combination, and the first small dropping pill and the second small dropping pill are located in the third shell layer; the preparation method of the bead-in-bead preparation comprises the following steps: respectively proportioning materials for preparing the large dropping pills and the small dropping pills, and respectively adding the materials into corresponding hoppers for dropping to form a seamless ca