The important strategic task of promoting high-quality development. The socialist market economic system is an important part of the basic socialist economic system and an important institutional guarantee for promoting economic development. The key to building a high-level socialist market economic system is "high-level". From the perspective of the historical vertical comparison within the system, the high level of the socialist market economic system should be higher than that of the previous stage, which is reflected in the more systematic, mature and stereotyped system itself. The connotation of the high-level socialist market economy system is not only contained in the "effective incentive of property rights, free flow of factors, flexible price response, fair and orderly competition, survival of the fittest" proposed by the 19th CPC National Congress, but also in the specific requirements of "building a unified market for the whole country, deepening the market-oriented reform of factors, and building a high standard market system" proposed in the report of the 20th CPC National Congress. These requirements are put forward in response to such practical problems as insufficient property rights incentives, insufficient free flow of factors, and non-standard competition environment in the last stage of development, which marks that we will promote the construction of the socialist market economy system with higher standards, so as to achieve the strategic goal of the socialist market economy system to a higher level. From the horizontal comparison of the external development of the system, the high level of the socialist market economic system should be reflected in its superiority over the market economic system of the capitalist society. Compared with the laissez-faire of the capitalist market economy, the socialist market economic system has found an economic system that can not only use capital to realize its own economic development, but also fully overcome the drawbacks brought by the logic of capital and benefit the whole people in the long-term exploration process. The high level of the socialist market economic system is mainly reflected in the strong ability to control and control the capital market, which is difficult for the market economy to reach under capitalist conditions. From the perspective of meeting development needs, the high level of the socialist market economic system is reflected in its stronger support for economic development. High-quality development is the primary task of building a socialist modern country in an all-round way, and the socialist market economic system is the institutional basis for achieving high-quality development. Whether the level of the socialist market economic system is "high" or not depends on whether its support for high-quality development is "strong" or not. To build a high-level socialist market economic system, we should aim at achieving high-quality development and building a socialist modern country in an all-round way