The invention relates to a synthetic process of a chemical substance, and particularly relates to a synthetic method for synthesizing (E)-2-[2-(6-chloro pyrimidine-4-yloxy)phenyl]-3-methoxy methacrylate and azoxystrobin; the method comprises the following steps: mixing a raw material of 3-(alpha-methoxy)methylene benzofuran-2-(3H)-ketone and potassium carbonate in a toluene solvent, cooling to 0-10 DEG C, adding sodium methoxide, reacting for 0.4-0.6 hours; adding 4,6-dichloropyrimidine and a catalyst of DABCO, reacting for 1-2 hours, filtering to remove inorganic salts, washing the filtrate with water, performing distillation to recover toluene; adding a catalyst of potassium bisulfate into the distillation residues of the above reaction, heating to 132-145 DEG C in a reduced-pressure condition for reaction; directly adding salicylonitrile to synthesize azoxystrobin or performing toluene dissolution, water washing, solvent recovery, recrystallization and filtration to obtain an intermediate. The production and synthesis of (E)-2-[2-(6-chloro pyrimidine-4-yloxy)phenyl]-3-methoxy methacrylate by the production process of the invention has high yield, and simple operations, and the used raw materials and processes are routine reagents and methods.