It analyses an excerpt from the post-modern novel Slaughterhouse-Five from the perspective of systemic functional lin-guistics. Through transitivity analysis and cohesion analysis, it finds that the novelist Kurt Vonnegut uses passive voice and the im-age of the moon to enhance the passivity and insanity of the anti-hero Bill Pilgrim respectively. Moreover, the fact that there is only one conjunction helps to form the feature of fragmentedness of the postmodern novel.