Great differences exist between the rural situations of North China and South China. It is difficult to adopt only one kind of biogas fermentation process to suit these different conditions. After the success of studies on dry fermentation with agricultural wastes, we studied the technology of combining dry and conventional, or wet, biogas fermentations. Dry fermentation was used to treat stalks and herbs, wet fermentation to treat human and animal excreta. Separating the treatment of stalks from excreta in dry fermentation can avoid the formation of crusts which lead to loss of gas-producing materials, and other faults of conventional, wet, biogas digesters treating stalks and excreta together.