2-Amino-5-bromo-3-morpholin-4-ylpyrazine was prepared from 2-amidopyrazine in an overall yield of 45.9% via bromination and substitution by morpholine, and its structure was confirmed by 1HNMR. The reaction conditions were optimized for temperature, reactant proportions, and reaction time. The optimized reaction conditions are as follows: n(2-Amidopyrazine):n(Bromine):n(Pyridine)=1:2.1:2.1, react at 40℃，kept in dark place; m(3,5-dibromopyrazin-2-amine):V(Morpholine)=1g:4mL, react at 80℃ for an hour. The improved process has the advantages of mild reaction conditions, simple operation, low cost and it is also suitable for large scale synthesis.