Pellet coating machine can be used for pellet coating of pharmaceutical, food and chemical products, achieving heat insulation, moisture prevention, slow release and controlled release, etc., and improving the added value of products. The equipment has a high degree of automation, accurate control, one-time completion in a closed state, good coating effect and less packaging material loss. By adding a spacer ring with openings at the upper and lower ends and corresponding sieve plates with different opening rates in the hopper, the movement of materials is controlled to form an orderly fluidized state. The liquid spraying is added into the system through the pneumatic nozzle installed in the center of the sieve plate, and the nozzle sprays liquid upward and from bottom to top, and its direction is the same as that of the material movement. There is a certain distance between the partition ring and the sieve plate to ensure that the material can flow smoothly from the outside of the partition ring to the partition ring, forming a circulating flow state. In the bottom spraying device, the fluidization state of pellets is very regular, and the pellets pass through the spraying liquid mist at regular intervals. The coating liquid is sprayed on the surface of particles with orderly movement near the nozzle, and the spreading of the liquid mist is also very uniform, and the formed coating film is uniform in thickness and has no pores, which will not cause poor film performance due to disorderly movement as in the top spraying.