Boiling dryer uses filtered clean air to undergo convective heat exchange in a heat exchanger, causing the air temperature to rise to a certain value and enter the main engine air duct. It is then distributed through valves and enters the boiling device. Wet materials enter the dryer from the feeder. Due to the effect of wind pressure, the material forms a boiling state inside the dryer, allowing the hot air to fully contact the material, enhancing the heat and mass transfer process, and promoting the evaporation and separation of moisture in the material in a short period of time. After the material is dried, it is discharged from the discharge port, and the exhaust gas is discharged from the top of the fluidized bed. The solid powder is recovered by the cyclone dust collector group and the bag dust collector before being discharged. This device performs negative pressure operation.