The invention discloses a method for quickly acclimating microorganism capable of degrading 2,4,6-trichlorophenol, and belongs to the technical field of biological sewage treatment. The method is characterized by taking an SBR (Sequencing Batch Reactor) as a main reaction device, inoculating activated sludge of a secondary settling pond of a municipal sewage treatment plant, and acclimating by adopting two stages, i.e., firstly introducing sewage containing the 2,4,6-trichlorophenol to enter the SBR for aeration acclimating, thus obtaining the activated sludge having certain degradation ability; then taking saccharose as a co-substrate organic carbon source, and introducing the saccharose into the SBR for aeration acclimating, thus finally obtaining aerobiotic activated sludge with higherability of degrading the 2,4,6-trichlorophenol. Through a two-stage acclimating method adopted by the invention, not only the microorganism with the higher ability of degrading the 2,4,6-trichlorophenol is enabled to be obtained within a shorter time, but also energy consumption is reduced, and a guiding significance in treating phenolic wastewater is obtained.