NOVELTY - Anaerobic digestion device comprises main body composed of solid phase reactor, acidizing collecting tank, liquid phase reactor, liquid phase reflux liquid collecting tank, and material conveying system. The solid phase reactor comprises three fermentation tanks, each is provided with material inlet, reflux liquid inlet, sprayer, marsh gas collecting opening, filter plate, acidifying liquid outlet, and vertical fermentation tank biogas outlet.    USE - Anaerobic digestion device.    ADVANTAGE - The fermentation tanks are connected in parallel, and connected with liquid reactor in series to realize acid and methane separation, thus preventing rancidity while providing stable gas. The anaerobic digestion device has simple and rational structure, provides quick fermentation speed, does not produce waste liquid, and satisfies scale production.    DETAILED DESCRIPTION - Anaerobic digestion device comprises main body composed of solid phase reactor, acidizing collecting tank, liquid phase reactor, liquid phase reflux liquid collecting tank, and material conveying system. The solid phase reactor comprises three fermentation tanks, each is provided with material inlet, reflux liquid inlet, sprayer, marsh gas collecting opening, filter plate, acidifying liquid outlet, and vertical fermentation tank biogas outlet. The liquid phase reactor comprises acidifying fluid inlet, return solution port, stirrer, and marsh gas collecting opening. The acidifying tank comprises collecting acidified collecting opening, stirrer, acidified outlet, and acidified collecting port connected with solid fermentation tanks via valve and pipeline. The acidified outlet is connected with acidified solution inlet of liquid phase reactor via pump and pipeline. The reflux liquid collecting tank comprises return liquid collecting opening, refluxing liquid outlet, and liquid phase reactor via pipeline port. The reflux liquid outlet pump is connected with solid phase yeast reflux liquid inlet of tank. The reflux liquid collecting tank is provided with spraying controller. The solid fermentation tank has upper part provided with filter plate and spiral conveyor. The acidified collecting tank is acidified concentration adjusting device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of anaerobic digestion device.