In this paper, by building the index system of pollutants discharge, the pollutant emissions intensity level of the provinces and the municipalities along the Yangtze River economic belt is calculated, by using Theil index and Gini coefficient and the logarithmic mean deviation of the differences between the three complementary indexes of pollutant emission intensity, the regional differences are comprehensively evaluated based on the provincial panel data, by the introduction of six explanatory variables such as the industrial structure level, economic development level, human capital level, the level of foreign investment, energy consumption level and urbanization level, the spatial econometric model is selected to make an empirical study on the influencing factors of pollutant emission intensity of the Yangtze River economic belt as a whole and regionally. The studying results show that the pollutant emission intensity of each region of the Yangtze River economic belt has significant differences. By taking 2011 as the turning point, the pollutant emission intensity of the Yangtze River economic belt shows an upward trend and then downward trend in general, among which the regions at the upper reaches have the most difference, followed by the middle reaches, and the regions at the lower reaches have the least difference. There are significant differences in the influencing factors of pollutant emission intensity in the three regions, and the significant heterogeneity exists in the effect of each explanatory variable on reducing pollutant emission intensity in different regions.