NOVELTY - Organic waste is processed by removing mechanical impurities from raw materials, desilting, sending to regulating tank, adjusting initial pH and water content, sending to hydrogen fermentation reactor, performing hydrogen fermentation acidification on small-molecule organic matter and produce hydrogen and carbon dioxide, discharging fermentation liquid, adjusting pH, sending to methane fermentation reactor, converting small-molecule organic matter into methane and carbon dioxide using methanogenic microorganisms, and precipitating fermentation liquid to obtain residue which is fertilizer.    USE - Processing of organic waste (claimed).    ADVANTAGE - Processing of organic waste has improved fermentation efficiency, waste treatment efficiency, and waste energy recovery rate and reduces environment pollution.    DETAILED DESCRIPTION - Organic waste is processed by removing mechanical impurities from raw materials, desilting, sending to regulating tank, adjusting initial pH and water content, sending to hydrogen fermentation reactor, performing hydrogen fermentation acidification on small-molecule organic matter and produce hydrogen and carbon dioxide, discharging fermentation liquid, adjusting pH, sending to methane fermentation reactor, converting small-molecule organic matter into methane and carbon dioxide using methanogenic microorganisms, precipitating fermentation liquid to obtain residue which is fertilizer, pretreating liquid part using aerobic treatment, physical adsorption, or electrochemical treatment to reduce chemical oxygen demand (COD) in fermentation liquid and convert ammonia nitrogen in fermentation liquid into ammonium salt, nitrate, and nitrite which are easy for microalgae to absorb, utilizing generated hydroalkyl by combusting hydroalkyl in heat power generating device and sending generated carbon dioxide to microalgae culture device as carbon source, or by sending hydroalkyl to microalgae culture device to remove carbon dioxide and purifying to obtain vehicle fuel, adjusting pH of pretreated fermentation liquid, adding essential trace elements, inoculating with microalgae, sending to microalgae culture device, using nitrogen and phosphorus in fermentation liquid to produce microalgae, sending algae solution in flocculation sedimentation tank, collecting supernatant in water tank, discharging part of water, recycling remaining part of water, concentrating flocculated algae solution, and sending concentrated algae solution with organic waste to hydrogen fermentation reactor.