In order to explore the contribution of transportation infrastructure as a public product to narrow the urban-rural income gap, the article is based on the theory of dual economic development and neoclassical economic theory, using spatial autocorrelation and spatial error models. Based on the panel data of 30 provincial administrative regions (except Tibet), the density of transportation infrastructure is introduced as the core explanatory variable, and the contribution of transportation infrastructure to improving the urban-rural income gap is discussed from a spatial perspective. The empirical results show that: the construction of highway transportation infrastructure helps to reduce the urban-rural income gap, among them, the first-level highway and the third-level highway have a positive spillover to the income gap, and the second-level highway has a negative overflow; railway infrastructure is the opposite. The results show that optimizing the investment structure of transportation infrastructure has important practical significance for narrowing the urban-rural income gap. With the declining marginal return of capital and the gradual disappearance of the demographic dividend advantage, a reasonable allocation of transportation infrastructure investment expenditures will promote economic growth towards efficiency transformation has become an urgent business.