Utilizing 229 county level regions in 32 pilot zones of the Entry Innovation in China from 2011 to 2018 as the object, this paper has empirically examined the impact effects and mechanisms on smog pollution in the pilot zones, whose results reveal that the Entry Innovation had a remarkable anti-smog effect, which arises through such mechanisms as promoting industrial structure optimization and increasing urban population clustering, but the effect is not so significant by reducing government intervention. The Entry Innovation's inhibitory influence on smog pollution in the pilot zones has certain lag effect; its anti-smog effect begins in the third year; as the implementation moves forward, the inhibitory effect on smog pollution becomes increasingly significant. In terms of geographical heterogeneity, the Entry Innovation has a more prominent impact on smog pollution in regions with low economic development levels or in the southern regions.