Separable words are a special language unit in Chinese. They have unique grammar characteristics. Because of the flexible transformation, it is a focal and difficult point in Chinese courses for foreigners. There is so much remarkable research achievements on separable words, while seldom of the researches are on separable words of the Outline of HSK Vocabulary. Basing on analysis, syntax structure, and Pragmatics of separable words, the author makes a thorough study to those words of the Outline of HSK Vocabulary.