The rapid penetration of digital technologies into the manufacturing sector has profoundly impacted the development of China’s manufacturing industry. This study aims to explore the role of the digital economy (DE) in promoting high-quality development in China’s manufacturing sector and to reveal the specific mechanisms through which it enhances the sustainability of manufacturing. Using panel data from 30 provinces across China for 2012–2022, this study employs an econometric model to conduct an empirical analysis. The results indicate that the DE significantly fosters high-quality manufacturing development (HQMD), particularly in eastern and central regions. Furthermore, by promoting the integration of productive services with manufacturing (IPSIM), the DE accelerates advancements in HQMD. The threshold effect analysis unveils a nonlinear relationship between the DE and HQMD. Based on these findings, policy recommendations are proposed to encourage balanced regional DE growth, strengthen digital innovation capacities, and catalyze the IPSIM. These insights provide critical implications for advancing high-quality development in China’s manufacturing sector.