The 19th National Congress of CPC took building modern economic system as a strategic goal of socialist economic reform in the new era China，which means that improving the socialist market economic system，taking supply-side structural reform as the focus of the current work，and actively promoting all-round changes of economic development will become new ways and new directions of changing the development model and optimizing the economic structure.The report of the 19th National Congress of CPC deployed some key strategic measures，which include the following： deepening the reform of the state-owned enterprises，developing mixed ownership economy，and Cultivate world-class enterprises with global competitiveness； deepening supply-side structural reform and making supply ＆ demand relationship be more balanced，reasonable and orderly； fully implementing market access negative list system，cleaning up and repealing regulations and practices that impede the unification of markets and fair competition.At the same time it also proposed specific and clear requirements for reform about financial system，fiscal system and policy，rights and responsibilities，and regional equilibrium.The theory of modern economic system embodies the innovation of theory and practice，whose prominent embodiments are “The Belt ＆ Road” policy，the innovation mode of internal ＆ external interaction and multi-win-win.China's proposal to build “the Community of Human Destiny” embodies China's desire and mind of its determination to develop with other countries in the world and move towards a new civilization and prosperity.Modern economic system realizes progressively the improvement of the living standards of the people in China and the improvement of the good life index，while creates a bright future for economic globalization and “the Community of Human Destiny” step by step.