The invention discloses a method for purifying 2,3-dichloropyridine. The method comprises the following steps: 1) placing crude 2,3-dichloropyridine into a reaction kettle, adding acid, then heating for reacting at 60 to 100 DEG C for 0.2-1 hour under the stirring condition, and separating obtained reaction liquid in a hot state to obtain an oil phase and a water phase; 2) adding alkali into the water phase obtained in the step 1) to regulate the pH to 8 to 12, then heating to boiling, performing steam distillation, collecting fractions of 100 to 103 DEG C, filtering the fractions, and dryinga filter cake to obtain 2,3-dichloropyridine. The method has the advantages of simple operation steps, high recovery rate of 2,3-dichloropyridine, high purity (purity of greater than or equal to 99.5percent by weight) and lower purification cost.