Fixed fluidized bed dry the wet material into bed contact with the hot air in the wind above board, material suspended in the air, the formation of fluidized state, with the increase of gas flow velocity to some degree, the material is boiling state in bed. Under the fluidized material particles and hot air heat transfer, mass transfer, dehydration, drying effect. It can be used for salt, chemical, pharmaceutical and food industries. It is suitable for drying and cooling of dry powder, granule materials.