A synthetic method of 2-chloro-5-trichloromethyl pyridine comprises the following steps of (1) synthesis of N-oxygen-3-methylpyridine: reacting by taking 3-methylpyridine as a raw material, glacial acetic acid as a solvent and 60% hydrogen peroxide as an oxidizing agent to obtain N-oxygen-3-methylpyridine; (2) synthesis of 2-chloro-5-methylpyridine: carrying out oriented chlorination on N-oxygen-3-methylpyridine by taking benzoyl chloride as a chlorinating agent to obtain 2-chloro-5-methylpyridine; (3) synthesis of 2-chloro-5-trichloromethyl pyridine: reacting by taking methyl ethyl ketone peroxide as an initiating agent to obtain a crude 2-chloro-5-trichloromethyl pyridine product; (4) refining of 2-chloro-5-trifluoromethyl pyridine: carrying out halogen exchange fluoridation reaction by taking excessive potassium fluoride as a fluorizating agent, dimethyl sulfoxide as a solvent and hexadecyl trimethyl ammonium bromide as a phase transfer catalyst, and rectifying and purifying to obtain a fine 2-chloro-5-trichloromethyl pyridine product.
