The Communist Manifesto has abundant legal thoughts. On the one hand, combining the two dimensions of history and value, Marx and Engels,on the basis of highly affirming the historical role of the bourgeoisie, criticized the material restriction, class limitation and form unity of their laws; on the other hand, after the proletariat seized power,Marx and Engels provided an overall idea for constructing the legal concept of the proletariat from the aspects of fighting for democracy, developing production and guaranteeing human rights. In the new era, a profound understanding of the legal thoughts in the Communist Manifesto is of great practical value for us in formulating laws that truly reflect the will of the people, improving the socialist democratic legal system, and participating in international legislation that conforms to fairness and justice.