Using the panel data on 93 prefecture-level cities in China from 2005 to 2018, this paper takes the UGB implementation in pilot cities as a quasi-natural experiment and uses the difference in difference model to empirically test the impact and mechanism of urban growth boundary (UGB) on urban industrial air pollution. The results show that the UGB policy has a significant role in reducing urban industrial air pollution. This conclusion remains valid after a series of robustness tests. Furthermore, we found that UGB reduces industrial air pollution through governance effects rather than spillover effects, and the negative impact is dynamic and sustainable. Hence, UGB contributes to the sustainable development of land urbanization in terms of reducing industrial air pollution. This research provides empirical evidence for the sustainable development of land urbanization and green development in China.