NOVELTY - The furnace has reactor connected with biomass material inlet feeder and steam generator through pipeline, for mixing and heating biomass materials and steam to generate combustible gas. An inert gas conveying pipeline conveys inert gas to the reactor, through a material outlet pipeline connected with material outlet opening for biomass powder of spiral material inlet device of inlet feeder. Several conically distributed stirring needles are arranged in tail end of screw located in the material outlet of the spiral material inlet device.    USE - Pressurized fluidized bed gasification furnace.    ADVANTAGE - The stirring performance of biomass material, and sealing effect of spiral material can be effectively improved in high pressure environment. The problems due to formation of low-density thin powder material can be prevented.    DETAILED DESCRIPTION - The inlet feeder has sealing hopper with top cover that cannot transmit magnet, stirring device and spiral material inlet device. A central hole is vertically extended from the top cover in the air pipeline in the sealing hopper, and connected with air supply source. A material outlet formed at lower portion of sealing hopper is connected with material inlet of spiral material inlet device. The stirring device comprises a motor, an outer magnetic rotor, an inner magnetic rotor and two symmetrical stirring bars. The outer magnetic rotor located at outer side of the top cover, uses the air pipeline extended in the central hole of the top cover as rotary shaft. The inner magnetic rotor located at inner side of the top cover corresponding to outer magnetic rotor, uses the air pipeline extended in the central hole of the top cover as rotary shaft. A motor drives the outer magnetic rotor through belt to drive inner magnetic rotor that drives two stirring bars connected with the inner magnetic rotor. The spiral material inlet device comprises a screw, a shell, inner magnetic rotor in screw side, outer magnetic rotor in three-phase asynchronous machine side and three-phase asynchronous motor. The inner magnetic rotor is located in outer side of cover and fixedly connected with rotary shaft of three-phase asynchronous motor. The outer magnetic rotor is driven by three-phase asynchronous motor to drive inner magnetic rotor so as to drive the screw that rotates in the shell. An INDEPENDENT CLAIM is included for operating method of pressurized fluidized bed gasification furnace.    DESCRIPTION OF DRAWING(S) - The drawing shows the hydraulic circuit diagram of the pressurized fluidized bed gasification furnace.