NOVELTY - Extracting humic acid from concentrated garbage percolate and treating wastewater comprises adding coagulant into concentrated garbage percolate, stirring uniformly, then adding coagulating auxiliary agent, settling for 40-60 minutes; then precipitating and separating, adjusting pH value of supernatant to 1.3-3.0; settling for 4.0-8.0 hours, then precipitating and separating, concentrating the precipitate for obtaining liquid humic acid with high concentration; and discharging when reaching the standard after being treated by advanced oxidation technology.    USE - Method for extracting humic acid from concentrated garbage percolate and treating wastewater (claimed).    ADVANTAGE - The total removal rates of chemical oxygen demand (COD) and total organic carbon (TOC) separately reach more than 96% and 97%, respectively. The separated semi solid of the humic acid can be used as organic fertilizer, thus, comprehensive utilization of the concentrated garbage percolate is realized. The targets of treating pollution and changing waste into valuable are obtained.    DETAILED DESCRIPTION - Extracting humic acid from concentrated garbage percolate and treating wastewater comprises:    (A) adding 0.15-0.35 wt.% coagulant into concentrated garbage percolate, stirring uniformly, then adding 0.005-0.01 wt.% coagulating auxiliary agent, settling for 40-60 minutes; where the coagulant is polymeric aluminum sulfate, polymeric ferric sulfate or polymeric ferric chloride; and the coagulating auxiliary agent is polyacrylamide;    (B) precipitating and separating for obtaining supernatant;    (C) adjusting pH value of the supernatant to 1.3-3.0;    (D) settling for 4.0-8.0 hours, then precipitating and separating, concentrating the precipitate for obtaining liquid humic acid with high concentration; and    (E) discharging the supernatant obtained via precipitating and separating when it reaches the standard after being treated by advanced oxidation technology, which comprises, in a catalytic reactor which takes sunlight as light source, adding oxidant and catalyst, oxidizing and degrading the supernatant for 20-30 hours; where the oxidant is hydrogen peroxide, and the catalyst is ferrous sulfate.