Abstract: County-level economy is the micro-foundation of the major strategic deployment of the whole country's economic development, and its integration process is an important indicator reflecting the economic development of a region. Based on the data taken from the years of 2000, 2010 and 2020, 9 representative indicators are chosen to construct the county-level economic integration analysis matrix of Chongqing, and the entropy weight TOPSIS method is adopted to calculate the weight of each indicator, and the corresponding comprehensive index of economic integration as well. At the same time, based on the comprehensive indices of economic integration in Chongqing and by aid of ArcGIS 10.2, a comprehensive level distribution map of economic integration rankings in Chongqing is made and an inverse distance weight interpolation map is charted. The results show that the maximum value of the comprehensive index of economic integration in Chongqing lies between 0.7 and 0.9, and the economic integration level of each district and county is characterized by a dynamic expansion and a spatial variation law of the fluctuating development in the core area. The research findings in this regard can help spot relevant problems and provide reference for the further development of the county-level economic integration in Chongqing.