Manifesto of the Communist Party is not only a classic work that systematically expounds the basic principles of Marxism, but provides a scientific methodology for studying and analyzing trends in social thought from a Marxist perspective. Taking historical materialism as the theoretical starting point and logical thread, Manifesto of the Communist Party clarifies the basic principles and methodology of scientifically analyzing trends in social thought. It proposes that the proletarian party has always faced the historical task of criticizing bourgeois culture and the historical mission of building socialist culture in the field of ideology and culture, reveals the manifestation of the “two inevitables” in the field of ideology and culture and the historical position and future of trends in social thought. It is a comprehensive analysis and critique of bourgeois ideology and all kinds of socalled “socialist” trends, and clarifies the ways and conditions for achieving the “two complete breaks”. An indepth investigation of the basic principles and scientific methods of Manifesto of the Communist Party in analyzing trends in social thought is of great theoretical value and practical significance for profoundly grasping the development laws and evolution of trends in social thought in the course of world history and building a socialist ideology with strong cohesive force and leading power.