The invention discloses a landfill leachate concentrated water treatment method. The method comprises the following steps: (1) pre-oxidation step: putting a certain quantity of sodium hypochlorite into landfill leachate concentrated water, aerating; (2) catalytic oxidation step: mixing the landfill leachate concentrated water aerated in the step (1) with a sodium hypochlorite solution again, introducing the mixed solution into an oxidation tower filled with a heterogeneous catalyst, introducing ozone into the oxidation tower in the form of a microbubble from the bottom part of the oxidation tower, and conducting catalytic oxidation. According to the method, the contents of ammonia nitrogen and refractory organics in the landfill leachate concentrated water are effectively reduced, the removal rate of COD and the B/C value are greatly increased, the biochemical load is reduced, the use ratio of the ozone is increased, and the cost is saved.