The invention belongs to the technical field of synthesis of medical and chemical engineering intermediates, and provides a synthetic method of arylnitrile compounds. A series of the arylnitrile compounds are synthesized through a heating reaction of a 2-phenylpyridine derivative and N-cyan-N-p-methoxyphenyl-p-benzenesulfonamide in a solvent with a manganese salt as a catalyst. The arylnitrile compounds are an important composition part of many drugs and bioactive molecules, have important applications in the fields of organic synthesis and medicinal chemistry, and have a broad market prospect. The method has the advantages of simple steps, easily obtained raw materials, mild reaction conditions, great use values and great social and economic benefits.