After the outbreak of COVID-19，protectionism and unilateralism have been prevalent in some countries. The central government has proposed “accelerating the formation of a new pattern of development in which the domestic general circulation plays a dominant role，both domestic and international dual circulations mutually promoting each other”. The Changjiang Middle Reaches Megalopolis should not only actively participate in the domestic cycle，but also make up the shortcomings of the international cycle. This study constructed the evaluation index system for the open economy development level of the Changjiang Middle Reaches Megalopolis from the three levels of foreign trade level，foreign investment and foreign economic levels，by using the entropy value method to to empirically demonstrate its spatial differences，research suggests that the open economy of each region have significant differences in development levels，its cause of formation heterogeneity，and the total retail sales of consumer goods，regional per capita GDP，the number of international friendship cities and the number of industrial enterprises above state designated scale are to have a significant impact factors. Therefore，in the new stage，major breakthroughs should be made in foreign trade business，foreign economic cooperation should be vigorously promoted，Encourage large-scale enterprises to lead the development of going global，so as to improve the open economic development level of the Changjiang Middle Reaches Megalopolis.