NOVELTY - Method for improving anaerobic digestion efficiency of organic wastes and content of methane in biogas, involves concentrating microorganism during whole anaerobic digestion process in two anaerobic digestion reactors connected in series, by concentrating hydrolysis fermented bacteria in the first section, concentrating acetic acid bacteria and methanogens in the second section, concentrating the microorganism in different sections, and feeding carbon dioxide and hydrogen produced in the first section into the second section, and producing methane.    USE - The method is useful for improving anaerobic digestion efficiency of organic wastes and content of methane in biogas (claimed).    ADVANTAGE - The method increases content of the methane in biogas and overall methane productivity of the system.    DETAILED DESCRIPTION - Method for improving anaerobic digestion efficiency of organic wastes and content of methane in biogas, involves concentrating microorganism during whole anaerobic digestion process in two anaerobic digestion reactors connected in series and feeding carbon dioxide and hydrogen produced in the first section into the anaerobic digestion system in the second section, and producing methane, by concentrating hydrolysis fermented bacteria in the first section, concentrating acetic acid bacteria and methanogens in the second section, and concentrating the microorganism in different sections by adjusting temperature and microorganism standing time in each section, by placing high organic waste in anaerobic reactor, sealing, maintaining continuous or semi-continuous feed controlled residence time in the anaerobic reactor for 2-4 days and controlling temperature to 50-60 degrees C, under anaerobic or anoxic conditions, obtaining enriched fermented bacteria, controlling hydrolysis fermented bacteria for producing acid and hydrogen gas comprising carbon dioxide, hydrogen and methane, using acetic acid bacteria and methanogens as a reinforcing material, maintaining continuous or semi-continuous feed controlled residence time in second section of the anaerobic reactor for 15-20 days, controlling the material under anaerobic condition, maintaining redox potential value (ORP) to be less than -300 mv and temperature of 35-37 degrees C, where the temperature fluctuation is not greater than plus minus 2 degrees C, controlling material to produce acetic acid and other short chain fatty acids, converting acetic acid into carbon dioxide and methane by methanogenic bacteria, and processing the obtained controlled microorganisms to obtain methane.