Use 2, 6-dichlorotoluene to chlorinate with chlorine and phosphorus trichloride under the action of ultraviolet rays to generate 2, 6-dichlorobenzylidene dichloride (also known as 2, 6-dichlorobenzylidene dichloride), and then hydrolyze with sulfuric acid and oxime with hydroxylamine hydrochloride to obtain 2, 6-dichlorobenzene oxime, which is chlorinated with chlorine and hydrogen, 6-Dichlorobenzene oxime chloride, and finally cyclized with ethyl acetoacetate with the participation of sodium hydroxide to obtain the product.