The Yangtze River Delta is the pilot area of China's economic development. Promoting its high-quality development can not only effectively optimize the allocation of resources among regions, but also effectively realize the integration and coordination among regions. However, in recent years, due to the outbreak of COVID-19, the economy of the Yangtze River Delta region has been impacted to a certain extent. This paper first expounds the significance of promoting the high-quality development of the economic integration of the Yangtze River Delta city group, then puts forward some main problems existing in the high-quality development of the economic integration of the Yangtze River Delta city group, and finally provides multiple paths for the high-quality development of the economic integration of the Yangtze River Delta city group.