In the era of the digital economy, the significance of green technological innovation for enterprises' sustainable development is pivotal. Effectively utilizing redundant resources is crucial to enterprises' sustainable development and innovation. Given this, we explore the impact of the digital economy and redundant resources on enterprises' green technology innovation. It uses a double fixed-effects model on the enterprise-level data of the Shanghai and Shenzhen stock exchanges from 2013 to 2021. The study shows that developing the digital economy can significantly enhance enterprises' green technology innovation. The effect is more obvious in high-tech enterprises, non-heavily polluted enterprises, enterprises in the eastern region, and non-state-owned enterprises. It also test the mediating effect of redundant resources and find that the digital economy can help enterprises exploit unabsorbed redundant resources, absorbed redundant resources, and organizational redundant resources, reduce the negative impacts of redundant resources on enterprises, and enhance their level of green technological innovation. It offer valuable policy suggestions.