Marx's Theses on Feuerbach is a bud of the formation of the new world outlook of Marxist philosophy. Although it is a thousand word essay, it has a very high position in the history of thought. An in-depth study will help to accurately grasp the connotation of Marx's thought and practice in the 21st century. This paper analyzes and studies the writing background of the Theses on Feuerbach, expounds the specific economic background, political background and ideological development process of the formation of Marx's new world outlook, expounds and interprets the specific content of the concept of practice in the Theses on Feuerbach, and finally discusses the historical and practical significance of the Theses on Feuerbach. Reviewing and studying the outline in the new era will help us correctly understand the dialectical relationship between practice and theory, deeply understand the standard of practical truth, and generally grasp the methodological value of Marxism.