Abstract: The study of water environment carrying capacity has an urgent and realistic significance for the sustainable development of socio-economic and ecology. The evaluation indicators were selected from the four perspectives of socio-economic, ecological, water quality, and water volume. The data of Jiangsu Province from 2004 to 2015 were statistically processed and calculated using the analytic hierarchy process and the vector norm method. The results show that the water environmental carrying capacity of Jiangsu Province as a whole showed a downward trend from 2004 to 2015 and reached the lowest value in 2008. From 2008 to 2015, the water environmental carrying capacity showed a trend of fluctuation and increase. The 2015 evaluation value is 0.342, but it is still lower than the multi-year average of 0.351. Therefore, Jiangsu Province must make breakthroughs in improving environmental protection investment, innovating technological equipment, optimizing, upgrading and shifting the industrial structure, so as to further enhance the local water environment carrying capacity.