Abstract: Traditionally,metonymy was often regarded as a means of figure of speech.However,in recent years,linguists think that metonymy is not just a means of figure of speech,but a way of people's cognition and behaviors and a phenomenon of language.This article has made an attempt to analyze and understand the origin and cognition of metonymy,the usage of metonymy,its cognition models and categories with some instances offered in order to find its laws of usages in language and offer some inspiration to people.