The article analyzes the contribution of the digital economy to the coordinated changes of industries and environment in Northern Anhui as part of the Yangtze River Delta. Through a balanced panel of 41 prefecture cities during 2011-2020 (N = 410), we construct a coordinated transformation index (CTI) of an industrial subsystem (structural advancement, rationalization, labour productivity, innovation capability, and digital integration) and an ecological subsystem (pollution intensity, resource pressure, environmental governance, and green coverage) through the entropy-weighting methodology. The Digital Financial Inclusion Index developed by Peking University is utilized as the proxy of the city level digital economy. The two-way fixed-effects model results in β = 0.087 (p < 0.01), indicating that it has a statistically significant positive effect on the CTI. Mechanism tests indicate three mediated pathways: industrial restructuring (the direct effect was decreased to 0.069), green innovation (decreased to 0.072), and resource allocation efficiency (decreased to 0.073). The heterogeneity analysis reveals higher heterogeneity in Northern Anhui (β=0.118) than in other Yangtze River Delta cities (β=0.081). It is also supported by a Spatial Durbin Model, which has both direct effect of 0.088 and a spillover effect of 0.052, which confirms cross-city complementarities. The results are similar to other proxies, lagged specifications and sample limitations. The online development serves as a structure integrator that can enhance both industrial and ecological performance simultaneously.