NOVELTY - Hard degraded biomass is catalytically pretreated by crushing straw, rice straw, bagasse, aquatic plants, animal dung, garbage and organic materials containing wastewater to obtain biomass powder; preparing suspended biomass slurry by adding pre-treated biomass powder with water, and regulating pH to 3-8; putting suspended biomass slurry into microwave electrodeless UV light catalytic reactor, adding catalyst, absorbing material and oxidant; and transforming suspended biomass slurry into reducing sugar and organic acid at 950-2450 MHz and 400-800 W using 2-12 for 0.5-2 hours.    USE - Method for catalytic pretreatment of hard degraded biomass for microbial production (claimed).    DETAILED DESCRIPTION - Catalytic pretreatment of hard degraded biomass comprises:    (A) pretreating biomass by sorting, cutting, drying at 50-100 degrees C and crushing straw, rice straw, bagasse, aquatic plants, animal dung, garbage and organic wastewater, and screening through 10-20 meshes to obtain biomass powder, where organic materials enriched with organic wastewater are coagulated, adsorbed and membrane-intercepted and the total organic carbon concentration of wastewater is 1000-10000 mg/L;    (B) preparing suspended biomass slurry by adding pre-treated biomass powder (10-100 g/L) with water, and regulating pH of suspended biomass slurry or concentrated wastewater to 3-8 using sulfuric acid and calcium hydroxide, while directly taking concentrated waste liquid;    (C) putting suspended biomass slurry or concentrated waste liquid into microwave electrodeless UV light catalytic reactor, adding microwave electrodeless UV light catalyst (1-20 g/L) and absorbing material (1-20 g/L) in the suspended biomass slurry or concentrated waste liquid;    (D) adding oxidant (1-10 g/L) and inletting compressed air at 0.1-0.8 MPa to mix; and    (E) transforming suspended biomass slurry into reducing sugar and organic acid, and converting organic components in wastewater to carbon dioxide and water and other components into organic acids with better biodegradability, at microwave frequency of 950-2450 MHz and microwave power of 400-800 W using 2-12 electrodeless UV lamps for 0.5-2 hours.