Cognitive linguistics holds that background knowledge and encyclopedic knowledge give the corresponding meaning of vocabulary，which provides a new perspective for lexical research. I try to discriminate the common Arabic synonyms based on the theory of the framework mechanism in cognitive linguistics. Starting from the explanatory power and rationality of the discrimination and analysis of Arabic synonyms in the framework mechanism，it is concluded that the students can guide students to interpret and discriminate between synonyms by stimulating the same frame，similar frame and opposing elements in the framework.