Based on the provincial panel data of the mainland China from 2000 to 2015, a threshold model is established to explore the relationship among industrial structure, technological progress and industrial wastewater discharge. The results show that: The influences of characteristics of the industrial structure on the industrial wastewater discharge are restricted by the double threshold effects of the technological progress, and when the technological progress is higher than the second threshold, the increase of the industrial economic proportion is no longer dependent on a greater increase in the industrial wastewater discharge. As a threshold variable, the technological progress in different regions of China has significant differences. The technological progress in the eastern, central and western regions has a decrease trend. The other influencing factors such as population size, output level and opening degree all play significant positive roles in promoting the industrial wastewater discharge, while the technological progress inhibits the industrial wastewater discharge. On this basis, some countermeasures and suggestions are put forward so as to reduce the level of regional industrial wastewater discharge and realize the goal of green development of industrial economy: improving the scientific and technological innovation system, increasing the investment in scientific and technological research and development, and constructing the compensation mechanism of trans-regional ecological technology.