Abstract: The primary stage of socialism is an accurate assessment of the stage of socialism that China is in. The report of the 20th CPC National Congress has made a new statement on the time span of the primary stage of socialism. To analyze this new change, we must fully understand the development process and theoretical evolution of the division of socialist stages, and pay special attention to the understanding generated in the practice of social and economic development and the major nodes of the development of the road of socialism with Chinese characteristics. Interactive comparison has become an important criterion for judging the stage of socialist development, especially around the early judgment of basically achieving modernization, which has become an important indicator for observing the development of the primary stage of socialism. On the basis of comparative analysis, we can continuously form predictable answers and theoretical reserves on the development standards of the primary stage of socialism.