The Twilight Saga written by American novelist Stephenie Meyer, tells the love story about an ordinary girl, Bella, and a handsome vampire, Edward. The novel sales hit the one hundred million mark from its release. And its Chinese version also gains much popularity among Chinese readers. Up to now, fantasy novel and its translation have drawn increasing attention of scholars from home and abroad. This paper focuses on a fantasy novel which has never been analyzed from this perspective. The paper makes a comparison between the English and Chinese versions of the novel Twilight from the perspective of Halliday’s three metafunctions, interpersonal function, ideational function and textual function, to give an in-depth study on the similarities and differences of two different languages and then put forward some beneficial suggestions for translators to understand and trans late fantasy novel comprehensively.