As digital technology and finance converge in the era of the digital economy, the digital transformation of banks can significantly contribute to economic development. This study investigates the impact of bank digital transformation on corporate digital technology innovation. By analyzing data from Chinese A-share listed firms and their lending banks from 2011 to 2021, our findings indicate that bank digital transformation facilitates corporate digital technology innovation primarily by reducing information asymmetry, alleviating financing constraints, and fostering innovation initiatives. These conclusions remain robust after conducting a series of robustness tests, including instrumental variable analysis and sensitivity assessments. Furthermore, this positive effect is more pronounced in high investment needs and high financial misallocation enterprises and is further amplified by the external financial and technological environment. Overall, our research provides valuable insights and implications for optimizing the digital transformation of banks, promoting corporate digital technology innovation, and enhancing policy frameworks.