Preparation of 2-amino-4-dimethylamino-6-trifluoroethoxy-1,3,5-triazine has the following steps: mix melamine and acetone, cooled to 0~10 with an ice bath, dropwise addition of aqueous ammonia solution, dropwise warming to 15~25 stirring reaction 1~3h. cooled the solution to 0~10 with an ice bath, dropwise addition of aqueous dimethylamine, dropwise stirring reaction 1~3h, filtration and water washing Get 2-amino-4-dimethylamino-6-chloro-1,3,5-triazine. Add 2-amino-4-dimethylamino-6-chloro-1,3,5-triazine obtained in step to the organic solution of sodium trifluoroethanol, and reflux the reaction for 2~6h, and then obtain it after post-treatment. The method of the present invention is easy to operate, the intermediate product does not need to be separated, the product yield is high, the purity is high, and it is easy to be produced industrially.
