The invention discloses a method for synthesizing ropinirole hydrochloride intermediate 2-methyl-3-nitrophenylacetic acid, in which 6-halo-2-nitrotoluene and ethyl haloacetate are combined under the action of a catalyst Reaction to obtain 2-methyl-3-nitrophenylacetic acid, 1) under protective gas, ethyl haloacetate, organic base, catalyst and solvent S1 are mixed, the temperature is raised to 100-120 ° C, and the pressure is raised to 3- At 5 atmospheres, add dropwise a mixture of 6-halogenated-2-nitrotoluene and solvent S2 for 30-60 minutes, increase the temperature to 130-155 °C, increase the pressure to 7-9 atmospheres, and react for 2-4 hours After cooling to room temperature, drip alkaline water, control the temperature not to exceed 90°C, after the dropwise addition, control the temperature to 120-140°C, pressure 2-3 atmospheres, and finish the reaction for 1-2 hours; 2) Filter and remove the precipitate after cooling , the filtrate was adjusted to pH 1 with acid water, added solvent S3 for extraction, layered, the organic layer was washed with water, dried, concentrated and evaporated to remove the solvent to obtain the product. The method has short steps, high yield and less pollution discharge.