NOVELTY - Two original common expanded granular sludge bed (EGSB) reactors are combined. A primary reactor is set symmetrically at one side and secondary reactor is set at other side. Rubbish percolation filtration liquid is passed to primary reactor for anaerobic digestion, and hydrogen is produced. A portion of outlet water is passed to secondary reactor for anaerobic digestion to produce methane. Content of hydrogen in gas produced by primary reactor is 19-33%. Content of methane in gas produced by secondary reactor is 67-68%. Thus, percolation filtration liquid is processed.    USE - Processing of rubbish percolation filtration liquid.    ADVANTAGE - The rubbish percolation filtration liquid is efficiently processed without affecting the environment, and contamination of waste liquid is reduced.    DETAILED DESCRIPTION - Two original common expanded granular sludge bed (EGSB) reactors are combined into a double-link reactor system. A primary reactor is set symmetrically at one side and secondary reactor is set at the other side, and reactors are connected via pipeline. A rubbish percolation filtration liquid is passed to primary reactor for anaerobic digestion, and hydrogen is produced. A portion of outlet water from primary reactor is passed to secondary reactor for anaerobic digestion to produce methane. The percolation filtration liquid is formed by primarily fermenting rubbish compost by alcoholic fermentation. The original water chemical oxygen demand (COD) concentration is 40000-60000 mg/L. The content of organic substance in rubbish percolation filtration liquid is more than 80%. The temperature of the primary and secondary reactors is 35 plus minus 1 degrees C, which is maintained using water bath clamping jacket at outer portion of the reactor main portion. The pH of the reaction main portion is set to 5-5.5 using hydrochloric acid and sodium hydroxide. The lifting flowing speed of liquid is 3 m/hour, and hydropower stopping time is set to 30 hours. The organic load is set to 1.4-1.67 gCOD alpha L.d. The pH of secondary reaction main portion is set to 6.8-7.2 using hydrochloric acid and sodium hydroxide. The lifting flowing speed of liquid is 3.2 m/hour. The hydropower stopping time is set to 43 hours. The organic load is 1.4-1.67 g COD alpha L.d. The content of hydrogen in the mixture gas produced by primary reactor is 19-33%. The content of methane in the mixture gas produced by the secondary reactor is 67-68%. The final COD removal rate is more than 90%. Thus, rubbish percolation filtration liquid is processed.