The invention provides a method for preparing lidocaine hydrochloride, and belongs to the technical field of anesthetic synthesis. The method comprises the following steps: by taking 2,6-xylenol as a raw material, Pd/C as a main catalyst and 2,6-dimethylcyclohexanone as a promoter, performing liquid phase amination with ammonia water at high temperature, thereby obtaining a midbody 2,6-dimethylaniline; enabling sodium methylate, 2,6-dimethylaniline and N,N-lignocaine methyl acetate as raw materials to react at 90-95 DEGC, distilling while reaction is performed to remove methanol till no methanol can be evaporated out, continuously reacting for 30 minutes, cooling to the room temperature, adding dichloroethane, washing with water, and leaving to stand to layer, thereby obtaining an organic layer, namely, a lidocaine based dichloroethane solution; further adding hydrochloric acid into the lidocaine based dichloroethane solution, adjusting the pH value to be 3.5-4 by using hydrogen chloride, adding activated carbon to reflux for 20-40 minutes, filtering, concentrating the filtrate, cooling, crystallizing, and dying, thereby obtaining lidocaine hydrochloride. The lidocaine hydrochloride prepared by using the method is simple in synthesis process and high in product purity, that is, the purity can be greater than 99%, and the total yield is greater than 84%.