Building on the basic views of synergy theory, we analyze the synergy mechanism between industrial agglomeration (the development of new clusters of industry) and urbanization (the increase in the population and level of development of urban areas). The data sources of some indicators use automatic sensors to collect information on electricity and sewage consumption. With the aid of nonparametric statistical analysis [bootstrap data envelopment analysis (DEA)] and the fuzzy mathematics membership degree concept, we construct a synergy effect measurement model of a composite system, which takes industrial agglomeration and urbanization as subsystems. We evaluate the synergetic development of an industrial agglomeration and urbanization composite system. The results show that the synergetic development level of the Jiangsu industrial agglomeration and urbanization composite system shows regional differences, which are affected by the socioeconomic factors of the two subsystems. They also show that the level of synergetic development of the industrial agglomeration and urbanization complex system is not high and needs to be further improved because it has not reached a stable state. Accordingly, we give some suggestions for enhancing the synergetic development level of industrial agglomeration and urbanization and promoting socioeconomic coordination and sustainable development. These include constructing a planning system for the interactive development of industrial agglomeration and urbanization, enhancing overall interactive development forces of industrial agglomeration and urbanization, guiding industrial agglomeration by urbanization points, applying an agglomeration strategy to optimize industrial layout, and reforming and innovating administrative management systems.