Abstract: The measure of temperature rising and heat preservation of membrane covered trough (MCT) dry fermentation biogas system, was brought forward as follows: firstly, the substrate’s temperature was increased to that of the upper limit of mesophilicly anaerobic digestion by the process of aerobic pre-treatment of the substrate; secondly, the substrate’s temperature was kept within the temperature range of mesophilicly anaerobic digestion by a good thermal insulation layer covering the MCT bioreactor. Experiment was held at the dry fermentation biogas pilot plant, and the results were described as follows: the substrate’s temperature changed mildly. The max of temperature drop in one day, occuring in the 9th day, was 0.5℃, the minimum of temperature drop in one day, occuring in the 3rd day , was 0.04℃; the substrate’s temperature was rised to 40.62℃ by aerobic pre-treatment process, decreased slowly during 21-day period of biogas fermentation and was 35.41℃ when anaerobic digestion finished; its average cubage biogas yield rate was 0.598 m3/(m3·d), methane content ranged between 55%-60%. Consequently, it is feasible to improve the cubage biogas yield rate and energy benefit of dry fermentation biogas plant by the measure of temperature improvement and heat preservation.