NOVELTY - Water washing-baking pretreatment of biomass by microwave pyrolysis polygeneration, comprises crushing biological feedstock, washing; adding the washed biomass into a pre-drying means for pre-drying; baking pretreatment; carrying out pyrolysis; passing the volatile substances into porous medium burner, combusting to produce high temperature flue gas; using the waste steam moisture and latent heat for recycling water; passing the low-temperature water, carrying out absorption pyrolysis to obtain bio-char sensible heat and, and discharging the aqueous washes into the storage tank.    USE - The method is useful for water washing-baking pretreatment of biomass by microwave pyrolysis polygeneration (claimed).    ADVANTAGE - The system has high energy efficiency, regulates biomass raw material, has safe operation system, and is economical.    DETAILED DESCRIPTION - Water washing-baking pretreatment of biomass by microwave pyrolysis polygeneration, comprises crushing biological feedstock, adding into the washing device, and washing with water 1-6 hours; adding the washed biomass into a pre-drying means for pre-drying, where the washed biomass is dried until the moisture content is 10-30%; placing the pre-dried biomass into a microwave reactor for baking pretreatment at 200-300 degrees C; placing the pre-baked solid product into the microwave pyrolysis reactor, carrying out pyrolysis at 500-550, passing the volatile gas via cascade condenser, and collecting the bio-oil, adding the collected bio-oil in the storage tank, passing the non-condensable gases from the spray condenser into gas cylinder, passing the biomass char into liquid-solid heat exchanger, cooling into the semi-coke collection boxes; passing the volatile substances generated during baking pretreatment into porous medium burner, combusting to produce high temperature flue gas, passing into pre-heat drying apparatus, to generate waste steam, and passing into the storage tank; using the waste steam moisture and latent heat in water storage tank for recycling water; passing the low-temperature water from the storage tank into liquid-solid heat exchanger, carrying out absorption pyrolysis to obtain bio-char sensible heat and then passing into the washing device, and discharging the aqueous washes from washing device into the storage tank. An INDEPENDENT CLAIM is also included for a system for water washing-baking pretreatment of biomass by microwave pyrolysis polygeneration, comprising washing tower (1), flue gas convection drying bed (2), low-power microwave baking furnace (3), high power microwave pyrolysis furnace (4), cascade condenser (5), gas tank, storage tank, oil pump, liquid-solid heat exchanger, low calorific value gas porous medium burner, water tank, circulating pump , and water pump; where the washing tower discharge port is connected to flue gas convection drying bed discharge port, and the flue gas convection drying bed discharge port is connected to low-power microwave baking oven discharge port; the low-power microwave baking furnace discharge port is connected to high power microwave pyrolysis furnace discharge port, the top of the low-power microwave baking furnace flue gas outlet is connected to the low calorie gas porous medium burner inlet; and the low calorific value gas s porous medium burner is connected to the flue gas convection drying bed flue gas inlet via pipeline; the outlet of waste steam flue gas convection drying bed is connected to the storage tank, the high power microwave pyrolysis furnace volatile gas discharge port is connected to spray condenser discharge port, the high power microwave pyrolysis furnace bio-char spout is connected to the liquid-solid heat exchanger discharge port; the cascade condenser bio-oil outlet is connected to the storage tank, the bottom outlet of the storage tank is connected to the cascade condenser spray liquid inlet via oil pump, the wash water outlet port of the washing tower is connected to the storage tank via oil pump, the water tank is connected to the liquid water outlet via the circulation pump and liquid-solid heat exchanger inlet, where the liquid-solid heat exchanger water outlet is connected to the water washing column inlet.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the system for water washing-baking pretreatment of biomass by microwave pyrolysis polygeneration.    Washing tower (1)    Flue gas convection drying bed (2)    Low-power microwave baking furnace (3)    High power microwave pyrolysis furnace (4)    Cascade condenser (5)