As one of the key elements of economic growth, labor force and its changes have a profound impact on China's economic and social development. Based on the data of the seventh national census and combined with the previous census and annual population data after the reform and opening up, this study analyzes the evolution of China's labor force structure and its possible impacts. The study finds that over the past 40 years, China's labor force structure has undergone fundamental changes, which has begun to face problems such as a decrease in the working-age population, increased support burdens, and uneven distribution of labor in regions. This has led to the adverse effects of reduced consumer demand, savings rate, and investment demand. However, changes in the labor structure have also brought certain developmental opportunities, including forcing technological progress and labor productivity, the general improvement of labor quality, and the continuous increase of labor wages. The study believes that in the 14th Five-Year Plan Period and beyond, we should seize the opportunities brought about by changes in the labor force structure, take the initiative to cope with the challenges, and achieve more adequate and higher-quality employment and sustained and stable development of the national economy.