NOVELTY - Treatment of sewage sludge, excrement and food waste comprises pre-treating unit, a tempering unit, middle-temperature "C" digesting unit, digestive juice dehydrating unit, methane purifying unit, and methane liquid treating unit. The pre-treating unit comprises first group of sewage sludge pre-treating technique carried out to homogenize sewage sludge, second group of excrement pre-treating technique carried out b to remove organic impurity in excrement and homogenizing, and third group of food waste pre-treating technique carried out to separate inorganic matter and organic matter in waste.    USE - Treatment of sewage sludge, excrement and food waste.    ADVANTAGE - The method has low investment, small occupied area, and low operating cost.    DETAILED DESCRIPTION - Treatment of sewage sludge, excrement and food waste comprises pre-treating unit, a tempering unit, middle-temperature "C" digesting unit, digestive juice dehydrating unit, methane purifying unit, and methane liquid treating unit. The pre-treating unit comprises first group of sewage sludge pre-treating technique carried out by diluting and stirring technique to primarily homogenize sewage sludge; second group of excrement pre-treating technique carried out by separating solid and liquid, modulating and stirring to remove organic impurity in excrement and homogenizing; third group of food waste pre-treating technique carried out by waste crushing, waste filtering and waste spiral squeezing technique to separate inorganic matter and organic matter in waste. The sewage sludge, excrement and food waste are pre-treated and fed to tempering unit at ratio of 6:1:2. The pollutant is pre-heated through high-temperature steam in tempering unit at 40 degrees C so that solid content of pollutant is further adjusted to 10% to meet requirement for consequent anaerobic treatment. The homogenized sewage sludge, excrement and food waste are pre-heated and conveyed to middle-temperature anaerobic digesting unit through screw rod pump, such that anaerobic environment in container is automatically controlled and adjusted to effect optimal anaerobic fermenting. The temperature of sludge in reactor is kept at 34-36 degrees C to perform middle-temperature anaerobic digestion. Hot water heating device is employed to insulate pot body out of digesting pot, while pollutant is then stirred through mechanical and water jet stirring. Certain space on upper part of reaction is kept for methane produced in anaerobic reaction. The methane in reactor is drawn from top of reactor through methane blowing fan, and then purified and fed to gas storing pot. The digestive juice is discharged from top of pot. The sewage sludge, excrement and food waste are treated through middle-temperature anaerobic digestion for 22 days in digestive juice dehydrating unit. The digestive liquid is then subjected to solid and liquid separation, and then dehydrated to obtain methane slag with 70% of water content, and methane liquid. The methane purifying unit also produces methane during combining and digesting sewage sludge, excrement and food waste at middle temperature. The methane is fed to desulfurizer in pressurization through blowing fan. One part of methane after being desulfurized is supplied to methane boiler room for pre-heating pollutant, insulating middle-temperature anaerobic digesting device, purifying and analyzing methane and supplying heat for factory in winter; and one part is fed to methane purifying system and fed to urban gas pipe network as urban supplementary air source. In methane liquid treating unit, methane liquid is fed to anaerobic ammoxidation integrated device provided by some company to be denitrified and then fed to phosphorus magnesium salt reaction pond. Magnesium oxide is added in pond so that phosphorus, magnesium and ammonium ion forms magnesium ammonium phosphate. Guanite also precipitates in phosphorus magnesium salt reaction pond. The methane is finally fed to phosphorus magnesium salt reaction pond to further remove phosphorus. Ferric trichloride is added in reactor to form iron phosphate precipitate. The separated precipitant can be mixed with guanite as fertilizer to be sold; and discharged water is treated to reach sewage discharge standard.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of a process for treating sewage sludge, excrement and food waste (Drawing includes non-English language text).