COP26 provided a roadmap to world leaders for taking policy measure for the climate change effects mitigation. In this regard, policy makers of major countries devoted their overwhelming support. Similarly, to achieve the targets of COP26, the role of industrial and energy sector critically important. In this paper, we have developed a new energy saving path to meet COP26 requirements through the industrial collaborative agglomeration index (ICAI) model which is constructed by taking location entropy of single industrial agglomeration as the basis. The super undesirable SBM (SUSBM) model is constructed to measure regional ecological efficiency (EE). Results show great differences in ICAI among the 3 regions and 11 provinces. Industrial collaborative agglomeration level of the upstream region shows fluctuation upward trend, while that of midstream and downstream regions shows fluctuation downward trend. The EE in downstream region is highest. The impact of ICAI on EE is significant and shows as a U-shaped curve. The increasing of proportion of the secondary industry in the industrial structure and increasing of per capita energy consumption inhibit the improvement of EE. The high proportion of non-state-owned economy in the economic system, the strengthening of environmental regulation intensity, and the improvement of economic development level and push technological innovation are conducive to the improvement of regional EE.