Presupposition is an important part either in semantics or in pragmatics. Humor is a higher realm in the process of human communication. In this article, the author focuses on the linguistic data from the Chinese talk show—Roast, to analyze the generation of verbal humor via several properties of pragmatic presupposition, including defeasibility, common ground and felicity or appropriateness. In this way, the author can provide implication and feasible suggestions for better development of talk shows in China.