The relationship between energy consumption and economic growth has been the research focus for scholars both at home and abroad. The role of electric power in the development of modern city has become more and more important. It is necessary to pursue the green environmental protection structure and mode of electricity consumption due to the dangerous nuclear power. The relationship between economic growth and electricity consumption in the city of Nanchang was analyzed using decoupling analysis. Economic development planning, industrial structure and population growth of city all can affect consumption of electric power resource. The city should adjust electric power consumption structure promptly and improve energy efficiency, meanwhile quicken construction of new energy and new technology.