In the past two decades, regional inequality in China's educational development, especially between urban and rural areas, has continued to narrow. An in-depth discussion of this phenomenon and the mechanisms behind it will not only help China build a high-quality educational system, but also draw lessons from Chinese practices to guide the reduction of global educational inequality. The comprehensive evaluation results show that China's rural EDL surpassed urban EDL in 2013; in 2003–2019, the urban/rural EDL increased from 0.29 to 0.22 to 0.50 and 0.54, respectively, and the urban-rural EII decreased from 1.31 to 0.92. Spatially, urban/rural EDL in the eastern and northeastern regions is higher than that in the central and western regions, the urban-rural EII in the eastern and northeastern regions is lower than that in the central and western regions. The CV and Theil index show that regional disparity in national urban/rural EDL has been narrowing, and regional inequality in urban-rural EII has also been declining; the decomposition of the Theil index indicates that these decreases in inequality are mainly from the reduction of the urban/rural educational development gap within the regions. The large-scale population migration driven by rapid industrialization and urbanization, and the adjustment of urban-rural and regional relationship promoted by the transformation of national policies such as regional coordinated development strategy and hukou system reform, are the main reasons for the evolution of regional inequality in China's urban and rural educational development.

Although China’s education development has made great progress, there are obvious regional differences in China’s educational development. A systematic investigation of the regional inequality in China’s educational development and its driving factors is of great significance for optimizing the allocation of educational resources and giving full play to the critical role of education in regional development. In addition, the research on the evolution and internal mechanism of educational development inequality in China can also provide experience and reference for the Global South. Therefore, we construct a comprehensive evaluation index system to measure the level of regional educational development, reveal the regional inequalities in China’s educational development, and employ spatial econometric model to dissect the factors influencing the regional inequalities. The results show that China’s educational development level continues to increasing from 2003 to 2020, but a significant decrease in its growth rate. In this process, regional differences in education inequality in China have gradually narrowed, which can be confirmed by changes in the Gini coefficient and Theil index. In terms of direct spillover effects, the per capita fiscal expenditure on education and urbanization rate have positive effects. In terms of indirect spillover effects, per capita GDP and per capita fiscal expenditure on education have negative effects, while population density and urbanization rate have positive effects. After replacing the weight matrix and removing the extreme values, the model also passes the robustness test. However, this mechanism is heterogeneous in different regions, therefore, we put forward the corresponding policies and measures according to the regional driving effects of influencing factors.