Abstract: A new type of large scale biogas dry fermentation system was developed, named as membrane covered trough biogas dry fermentation system, including membrane covered trough bioreactor and accessorial equipment. It achieved the goal of convenient transformation between anaerobic and aerobic conditions by soft tube inflating pressure seal linkup, solving the problem of large scale raw material input and output. It was easy to estimate biogas quantity in the bioreactor because of its flexible structure, being helpful for safe biogas production. It could run with mesophilic anaerobic process(35－42℃) by gaining heat energy from aerobic pre-treatment and heat energy preservation during anaerobic digestion, in no need of additional heat resource. It could satisfy the need of different scale biogas yields by adding or reducing the number of membrane covered trough bioreactor. Membrane covered trough biogas dry fermentation pilot project was constructed, the cubage of which was 180 m3. Its cubage biogas yield rate was 0.598 m3/(m3?d), methane content ranged between 55%－60%.