Since 2000, China has entered the stage of comprehensively building a moderately prosperous society that benefits more than one billion people, and has achieved its first centenary goal in 20 years. This piece systematically evaluates and summarizes the building of a well-off society in an all-round way according to the method of consistent goals, including four main goals and quantitative indicators of economic development, innovation drive, people’s livelihood and well-being, and resources and environment. The basic conclusions of the evaluation are: In the first 20 years of the twenty-first century, China firmly grasped an extremely valuable period full of strategic development opportunities, developed rapidly and comprehensively, and achieved historical unprecedented development. There were great changes and great progress, enabling China to quickly move to becoming a global power. The great rejuvenation of the Chinese nation is going hand in hand with the major, unprecedented changes in the world today. Additionally, in this period, China has made nine major contributions to the world, including eradicating absolute poverty, promoting economic growth, promoting industrialization, promoting trade growth, increasing global investment, promoting technological innovation, promoting scientific research, developing green energy, and promoting a peaceful development strategy. Finally, five important implications of these events can be summarized.