In order to promote high-quality development, we must accelerate the construction of a new development pattern with the domestic big cycle as the main body and the domestic and international double cycles promoting each other. This is a major decision made according to the changes in China's development stage, environment and conditions, especially based on the changes in China's comparative advantage, and is a major strategic task related to China's overall development. It is of great significance to accurately understand the connotation and significance of building a new development pattern from the overall perspective for building a socialist modern country with high-quality development as the primary task. From the perspective of supply and demand, building a new development pattern attaches importance to both the supply side and the demand side, both of which complement and promote each other. The national economic cycle is a cyclic and continuous process in which various factors of production or commodities are allocated in a market-oriented way based on the relationship between supply and demand. From the supply side, changes in China's development stage, environment and conditions make it difficult to sustain the old combination of production functions. The proposal to deepen the supply-side structural reform means that we continue to use reform methods to promote structural adjustment, reduce ineffective and low-end supply, expand effective and high-end supply, enhance the adaptability and flexibility of the supply structure to changes in demand, improve total factor productivity, and promote economic growth. From the demand side, we firmly grasp the strategic base point of expanding domestic demand, so that production, distribution, circulation and consumption rely more on the domestic market and form a virtuous circle of the national economy. From the perspective of time, building a new development pattern is neither a short-term strategy nor an expedient, but a medium - and long-term development strategy adjustment to grasp the development initiative. China has been the second largest economy and the largest manufacturing country in the world for more than ten years. According to the data, from 2013 to 2021, China's average contribution rate to world economic growth reached 38.6%, more than the sum of the contribution rates of G7 countries. At the same time, China has a population of more than 1.4 billion and a middle-income group of more than 400 million. The per capita GDP has reached US $12700, making it the largest and most potential consumer market in the world. China has 169 million market entities and more than 170 million talents with higher education or various professional skills. Its R&D capability has been continuously improved and has a solid and strong supply base. Such a market with huge growth space and potential determines that we always have the advantages and inherent ability to build a new development pattern. Therefore, it is our primary consideration to adjust the relationship between the domestic economic cycle and the international economic cycle according to our own development needs. The construction of a new development pattern conforms to the inherent needs of China's economic restructuring and promotion of high-quality development. From the perspective of space, the construction of a new development pattern is not self-styled, nor is it independent, but a big cycle based on a unified national market. First of all, "taking the domestic circulation as the main body" is by no means domestic