Abstract: The assessment and summary of building a moderately prosperous society in all respects has the ideological value of unifying ideological understanding and strengthening political identity; it has the historical value of launching the Second Centennial Goal and expanding the concept and practice of community of common destiny for all mankind. The basic principles that should be followed in the assessment and summary work are the combination of comprehensive and factor synergy, qualitative and quantitative assessments, systematic and focused assessments, and dynamic and static assessments. Looking back on the 40-year construction of a moderately prosperous society in all respects, the basic experiences can be summarized as follows: it is necessary to proceed from reality and to advance the work step by step; it is an important grasp to make a good combination of the Party's great layout advantages and the institutional advantages of concentrating its efforts on major events, and it is the goal to take care of the "Chinese experience" and enhance the people's sense of acquisition, happiness and security.