Belonging to the field of drug synthesis, the invention relates to a new method for preparation of the netupitant key intermediate N-methyl-4-(2-methyl phenyl)-6-(4-methyl-1-piperazinyl)-3-pyridylamine. The method comprises the steps of: 1) in certain solvent, subjecting 6-(4-methyl-1-piperazinyl)-4-(2-methyl phenyl)nicotinamide (formula I compound) and ROX (X=H or Na) to Hoffman degradation reaction under the condition of iodobenzene diacetate or substituted Iodobenzene diacetate, thus obtaining a formula II compound; and 2) carrying out reduction reaction on the formula II compound to obtain N-methyl-4-(2-methyl phenyl)-6-(4-methyl-1-piperazinyl)-3-pyridylamine (formula III compound). The new method for preparation of the netupitant key intermediate N-methyl-4-(2-methyl phenyl)-6-(4-methyl-1-piperazinyl)-3-pyridylamine has the advantages of easily available production raw materials, mild reaction conditions and simple operation, avoids application of strong base and controlled reagents, and provides an environment-friendly generation process.