This study investigates the mechanisms through which government subsidies and digital transformation affect the enhancement of new quality productive forces in manufacturing enterprises. Based on panel data from A-share listed companies in Shanghai and Shenzhen between 2011 and 2022, the empirical findings are as follows: ①Government subsidies significantly promote the development of new quality productive forces, but an excessively low subsidy level may yield adverse effects. ②The relationship between digital transformation and new quality productive forces exhibits a U-shaped pattern. As digital transformation progresses from a low to a moderate level, its marginal effect decreases; however, once a critical threshold is exceeded, digital transformation strongly facilitates the growth of new quality productive forces. Moreover, digital transformation serves as a mediating role in this process. ③The driving effect of digital transformation shows significant heterogeneity across firm life cycle stages, industry types, and pollution characteristics. Compared to initial-stage firms, the impact is most pronounced for enterprises in the decline stage. High-tech industries display a more evident U-shaped relationship, whereas high-pollution industries show a different pattern.