The invention discloses a method for synthesizing 5-chlorine-4-formyl oxazole. The synthetic method comprise the steps of undergoing a reaction of a glycine derivative, bis(trichloromethyl) carbonic ester and a formamide compound in an organic solvent at a temperature of -20 DEG C to 150 DEG C for 1-10 hours and separating the reaction liquid after the reaction ends to obtain the 5-chlorine-4-formyl oxazole shown as a formula (I), wherein the ratio of the amount of substances of the glycine derivative to the formamide compound to the bis(trichloromethyl) carbonic ester is 1: (1-20): (0.33-3.3). In the invention, an acyl glycine derivative is firstly used as a raw material to synthesize a novel compound without using phosphorus oxychloride, thereby avoiding the phosphorus pollution and reducing the treatment cost of the three wastes; moreover, the reaction selectivity is good; the yield is high; the post treatment is simple and the product is easy to separate.