Under the overall strategic background of the great changes in the world unseen in a century and the great rejuvenation of the Chinese nation, historic changes have taken place in the size, structure and content of the Chinese economy, and historic achievements have been made. As China's economy enters the stage of high-quality development, it is necessary to clearly delineate the path and mechanism of economic growth, the practical direction and method of common prosperity and the mechanism of coordinated economic development. Accordingly, the study of quantitative economics also needs new paradigms, new ideas and new ideas, so as to provide scientific evaluation and clear guidance for the practical problems and policies of China's economic development under the great changes in the world.