In the context of increasingly severe global environmental issues, the manufacturing industry, as a vital pillar of the national economy, faces an urgent challenge. This challenge is how to achieve the integrated development of digital transformation and green transformation in order to actively respond to the major strategic demands of the "dual carbon goals" and green transformation. This research focuses on the core question of "how digital transformation promotes green transformation in the manufacturing industry." By utilizing data from A-share manufacturing listed companies from 2013 to 2022, the study deeply analyzes the dynamic relationship among digital transformation, green investment, green transformation, and industrial policy, while employing fixed-effects models and statistical analysis methods. The findings reveal that digital transformation has a significant driving effect on green transformation in the manufacturing industry. However, green investment exhibits a 'suppression effect' in this process, meaning that the current insufficient scale and unreasonable structure of green investment have led to negative effects. Furthermore, industrial policy plays an important regulatory role in the integrated development of digital transformation and green transformation. This research not only unveils the impact path of digital transformation driving green transformation but also deconstructs the mechanism of "dual transformation," providing theoretical and empirical support for the integrated development of digital transformation and green transformation in the manufacturing industry.