Based on data from Chinese A-share listed companies on the Shanghai and Shenzhen stock exchanges from 2010 to 2022, this study examines the impact and mechanism of digital transformation on idle fixed assets of enterprises. The study finds that digital transformation and idle fixed assets of enterprises exhibit an inverted U-shaped relationship. Mechanism analysis shows that digital transformation affects idle fixed assets of enterprises through its impact on fixed asset utilization, investment in fixed asset renewal and in reconstruction, and the disposal speed of fixed assets. Heterogeneity analysis indicates that when enterprises have a higher level of business complexity, belong to non-labor-intensive industries, and are located in the eastern region, the effect of digital transformation in revitalizing idle fixed assets is more significant. Further research finds that digital transformation’s revitalization of idle fixed assets further promotes enterprise fixed asset investment.