Thiouracil is an important pharmaceutical intermediate; it not only has antibacterial activity, but also can be used to treat hyperthyroidism. It inhibits the production of thyroxine by inhibiting the peroxidase system in the thyroid gland, thereby achieving the effect of treating hyperthyroidism. Therefore, it is of great significance to study the optimization of its synthesis process. The current synthesis method is mainly obtained by condensation of ethyl acetoacetate and thiourea under the catalysis of alkaline conditions, and the commonly used catalyst is sodium alkoxide.