Construction land reduction is an important means of promoting the effective allocation of factors and the optimization of industrial structure. Based on analyses of the impact mechanism of construction land reduction on industrial structure rationalization and supererogation, this study adopts the difference‐in‐difference model and threshold regression model to analyze the effects of construction land reduction. The results are as follows: (1) Construction land reduction significantly improves industrial structure rationalization and supererogation, and the positive effect clearly accumulates over time. After PSM‐DID and other series of robustness tests, the conclusion is still valid. (2) Construction land reduction in the outer suburban areas has a greater positive impact on industrial structure rationalization and supererogation than that in other suburban areas. (3) When the scale of the reduction exceeds a certain threshold, rural financial development can significantly promote industrial structure rationalization and supererogation. It is necessary to rationally plan the layout of industry, establish a mechanism of cross‐regional allocation of the reduction index, and provide replicable experiences for popularizing construction land reduction throughout the whole country.