The present invention discloses a 2, 3-dichloropyridine preparation method comprising the following steps: (1) 2,3-dimethylamide
pyridine is dissolved in water, then a caustic soda
aqueous solution and a
sodium hypochlorite aqueous solution are successively added, after the addition is completed, the mixture is heated for full reaction, after the reaction is completed, the
system is adjusted to be neutral or acidic by use of
hydrochloric acid, and water is removed by
distillation to obtain a 2,3-diaminopyridine crude product; (2) the 2,3-diaminopyridine crude product is dissolved in
hydrochloric acid, a catalyst is added, then a
sodium nitrite aqueous solution is added dropwise, after the addition is complete, the2,3-diaminopyridine crude product is completely reacted, and after the reaction is completed, a 2, 3-dichloropyridine crude product is obtained by
distillation; and (3) the 2, 3-dichloropyridine crude product is added into an
organic solvent for complete dissolving, then cooled for recrystallization, crystals are filtered off and dried to obtain a 2, 3-dichloropyridine finished product. The method avoids the problem of very low tendency for side effects of 2-site chlorination, the production process is simple, the reaction is smooth and steady, production cost is low, product yield is high, and product purity is high.