With the emergence of a large number of network languages in recent years, how to understand and effectively use them in the different context is particularly important. From the perspective of cognitive linguistics, this paper studies the semantic derivation mechanism of the new Internet word “Ke”. By discussing the evolution of word meaning based on idealized cognitive model and the new network meaning added by metaphor mapping, this paper further clarifies the importance of popular subjective cognition for the emergence and development of a new word. The combination of cognition and language phenomenon can effectively promote the solution of problems, in order to help the public better understand network language.