Based on the objective law of China’s socialist development, this paper explains the theoretical origin and practical process of realizing socialist modernization, and explores the evolution and trajectory of the life cycle of socialist development. On this basis, based on the strategic goal of basically realizing socialist modernization in 2035, this paper makes a trend judgment and prediction by combining qualitative analysis with quantitative calculation, and holds that China is gradually completing the main tasks in the primary stage of socialism and entering a new 15-year transition period (2020–2035), which will undergo fundamental, historic and all-round major changes, embody new trends and features, and realize the transition from the primary stage of socialism to a more advanced development stage. In 2020, China has completed its first centennial goal by building a moderately prosperous society in all respects; With 2035 as the new mark, China aims to basically realize socialist modernization and usher in the intermediate stage of socialism; By 2049, the centenary of the founding of People’s Republic of China, China will build China into a great modern socialist country that is prosperous, strong, democratic, culturally advanced, harmonious, and beautiful, thus realizing the second centennial goal; By 2078, the 100th anniversary of the reform and opening up, China plan to become a developed country with socialist modernization in an all-round way, achieving the third centennial goal; And by the end of the twenty-first century, the ultimate goal is to realize the common aspiration of the people of all ethnic groups in China: to realize the “Chinese Dream”—the great rejuvenation of the Chinese nation.