NOVELTY - A crop straw joint fermentation device comprises preprocessing reaction tank and anaerobic fermentation tank in which preprocessing reaction tank is provided with jacket, tank body which has upper sealing head at top, lower sealing head at bottom, oxygen pipe, agitating and transporting device, and discharging pipe set at lower end in which materials from preprocessing reaction tank is transferred to fermentation tank through discharging pipe, feeding material port connected to atmosphere, material sampling port, and outlet port, and anaerobic fermentation tank is composed of jacket (33).    USE - A crop straw joint fermentation device (claimed).    ADVANTAGE - Crop straw joint fermentation device is environment-friendly, has simple structure and high conversion rate, recovers leachate and biogas, greatly increases biomass straw gas production potential, increases anaerobic fermentation gas generating efficiency, shortens fermentation time, and reduces energy consumption, and preprocessing reaction tank is capable of aerobic, micro-aerobic, or anaerobic pretreatment of crop straw and promotes decomposition of lignocellulose.    DETAILED DESCRIPTION - A crop straw joint fermentation device comprises preprocessing reaction tank and anaerobic fermentation tank in which preprocessing reaction tank is provided with jacket, tank body which has upper sealing head at top, lower sealing head at bottom, oxygen pipe, agitating and transporting device, and discharging pipe set at lower end in which materials from preprocessing reaction tank is transferred to fermentation tank through discharging pipe, feeding material port connected to atmosphere, material sampling port, and outlet port, and anaerobic fermentation tank is composed of jacket (33), tank body (32) which is provided with upper sealing head (34) at upper end which has gas collecting port (36) connected to atmosphere and organic wastewater inlet pipe (37), lower sealing head (35) at lower end, liquid material outlet, discharge hole (38), stirring device, and drain outlet (40) set at the lower end.    DESCRIPTION OF DRAWING(S) - The drawing shows a structural schematic diagram of a buit-in preprocessing reaction tank.    Tank body (32)    Jacket (33)    Upper sealing head (34)    Lower sealing head (35)    Gas collecting port (36)    Organic wastewater inlet pipe (37)    Discharge hole (38)    Drain outlet (40)