Based on China’s provincial panel data from 2007 to 2017, this paper constructs a comprehensive indicator system for high-quality development of manufacturing from eight dimensions. Using the composite entropy weights method, kernel density estimation (KDE) and exploratory spatial data analysis (ESDA) to investigate its spatiotemporal evolution and spatial correlation characteristics. The results show that: (1) The high-quality development of the manufacturing industry shows a steady upward trend, but each dimension (subsystem) is quite different and can be divided into three types: growth type, flat type, and attenuation type. (2) The spatial distribution of the high-quality development of the manufacturing industry is highly consistent with the “Hu Huanyong Line”, and the overall layout is “high in the east and low in the west, high in the south and low in the north”. Seventy percent of the provinces are below the average level, with large interprovincial differences and significant spatial imbalance. (3) The high-quality development of the interprovincial manufacturing industry shows obvious spatial positive correlation. The hot spots are more active, and the spatial spillover effect is stronger—the Yangtze River Delta is the core, spreading outward in circles, and the main direction of diffusion is “from north to south”. In contrast, the cold spot area develops slowly and moves from south to north. Therefore, China should pay more attention to the “Botai Line”, which is perpendicular to the Hu Huanyong Line, and formulate differentiated development strategies to promote the coordinated development of the manufacturing industry.

With the acceleration of informatization, the spatial layout of economic activities has gradually shifted from “transportation cost + labor force” to “information + technology”. As a new generation of information, the digital economy has a profound impact on the spatial layout of the manufacturing industry. Based on the data of China’s listed manufacturing companies from 2001 to 2020, this paper aims to assess the effect of the digital economy on manufacturing agglomeration and identify the transmission mechanism of this effect. The results show the following: (1) The digital economy significantly promotes the geographical agglomeration of the manufacturing industry, which is still valid on the basis of a series of robustness and endogeneity tests. (2) Mechanism analysis shows that the digital economy promotes manufacturing agglomeration by reducing transaction costs, increasing market potential and enhancing knowledge spillover. (3) Heterogeneity analysis shows that the effect is more significant in the samples of large enterprises, high-tech manufacturing, central and western regions, small and medium-sized cities and the west side of the “Hu Huanyong Line”, which will greatly help the layout of the manufacturing industry break through the “Hu Huanyong Line” to achieve balanced development. (4) Globalization, localization and human capital play a significant positive moderating role in the process. This paper provides microevidence for the integration of digitalization and industrialization. Furthermore, it has important implications for the formulation of digital economy policy, the high-quality development of the manufacturing industry and the continuous promotion of regional coordinated development.