As the root of literary theory, the essence of literature has always been regarded as the core and cornerstone of literary theory, and it is also the primary problem that every researcher of literary theory cannot avoid. Only by clarifying the essence of literature can we start from its basic nature and explore all aspects of literature. This paper discusses the academic rationality and parasitism of literary theory from the perspective of anti essentialism. Firstly, the paper discusses the transformation from literary theory to cultural research, and then focuses on the parasitism of literary theory. The parasitic nature of multidisciplinary and multi doctrine makes literary theory open and pluralistic, and makes it a battlefield full of contradictions, conflicts and controversies.