NOVELTY - Sewage treatment system comprises: a primary solid-liquid separating device for separating solid waste and liquid waste in the cultivation farm; a waste liquid treatment system for depositing the separated waste liquid and filtering to obtain the residue-free waste liquid and precipitate concentrated slurry, then forming methane and low-concentration methane liquid; a high-concentration slurry treatment system for mixing the separated solid waste and the precipitate of the waste liquid treatment system to obtain high-concentration slurry; and an organic fertilizer processing system.    USE - The system is useful for treating cultivation waste.    ADVANTAGE - The system: proceeds a concentrated separation of cultivation waste according to the commercial value; processes the low-concentration residue-free waste liquid by anaerobic methane treatment so as to reuse in the field; processes the waste material after high-concentration slurry by anaerobic methane treatment via solid-liquid separation to produce high-concentration liquid and solid commodity fertilizer, which can be used together by the construction of farm, which is suitable for organic waste disposal of medium and large livestock waste as cattle, sheep or pig; uses waste which is more complete relative to the discharging and transportation treatment manners; and can provide methane as well as the raw materials for irrigation water and commercial fertilizer, thus reducing the cultivation cost, eliminating the bad effects to the periphery environment caused by cultivation.    DETAILED DESCRIPTION - Sewage treatment system comprises: a primary solid-liquid separating device for separating solid waste and liquid waste in the cultivation farm; a waste liquid treatment system for depositing the separated waste liquid and filtering to obtain the residue-free waste liquid and precipitate concentrated slurry, then forming methane and low-concentration methane liquid by anaerobic methane treatment; a high-concentration slurry treatment system for mixing the separated solid waste and the precipitate of the waste liquid treatment system to obtain high-concentration slurry, then forming the methane by anaerobic methane treatment, and the high-concentration methane liquid and solid waste residue; and an organic fertilizer processing system for processing the high concentration methane liquid to liquid fertilizer and processing the solid residue to solid fertilizer. An INDEPENDENT CLAIM is also included for treating cultivation waste by sewage treatment system, comprises: (a) separating the mixed waste of cultivation field to liquid waste and solid waste; (b1) concentrating the precipitate of step (a), filtering to form residue-free waste liquid, forming the low-concentration methane liquid and methane of the residue-free waste liquid, (b2) mixing the solid waste with precipitate slurry of step (b) to form high-concentration slurry, forming methane, high-concentration methane and waste slurry by the high concentration slurry; (c1) purifying the methane of step (b1) and (b2) for storing, (c2) storing the low concentration methane to be used in field, (c3) forming residue-free high-concentration methane liquid by the high-concentration methane liquid of step (b2), and processing the residue-free high-concentration methane liquid to liquid fertilizer, dehydrating the waste slurry of step (b2) to form solid waste residue and processing the solid waste residue to solid fertilizer.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the sewage treatment system.