The pollution reduction effect of regional development could be analyzed more comprehensively from the perspectives of coordinated development and differentiated development. Based on the theory of regional coordinated development, this paper used panel data for cities in the Yangtze River Economic Belt from 2008 to 2017, adopted the spatial autocorrelation method and spatial econometric model to analyze the spatial and temporal distribution pattern of environmental pollution emission, regional coordination and differentiated development degree in the Yangtze River Economic Belt, analyzed the impact of regional differentiated coordinated development on pollution emission reduction in local and surrounding cities, and discussed the spatial spillover effect of regional differentiated coordinated development on pollution emission and its boundary test. The results showed that (1) at the overall level of the Yangtze River Economic Belt, coordinated regional development and differentiated regional development have significantly reduced pollution emissions and present complementary effects on pollution emission reductions; (2) an obvious spatial spillover effect was observed for the impact of regional coordinated and differential development on pollution reduction, a negative spatial spillover coefficient was observed for different urban economic circles, and an obvious inverted U-shaped trend occurred in the impact degree with increasing distance, with a 500 km range of urban economic circles considered a turning point; and (3) a heterogeneity test used the three major regions and sub-cities of the Yangtze River Economic Belt to verify and analyze the impacts of regional coordinated and differential development on pollution emissions, which showed that there was obvious spatial heterogeneity at different levels. Based on the above results, policy suggestions for decreasing pollution emissions in the process of differentiated coordinated development of the Yangtze River Economic Belt were proposed.