Taking Chinese A-share listed private enterprises from 2014 to 2021 as the research object, this study empirically examines the impact of digital inclusive finance development on inefficient investment of private enterprises. Research has found that digital inclusive finance effectively suppresses inefficient investment by private enterprises, and reducing agency costs and alleviating financial risks are the main paths through which digital inclusive finance acts on inefficient investment by enterprises. Based on the perspective of the enterprise lifecycle, digital inclusive finance has a significant inhibitory effect on inefficient investment of enterprises in the growth and maturity stages, but it is not significant for inefficient investment of enterprises in the recession stage. In addition, the study also found that in private enterprises located in the eastern region with a high proportion of management shareholding, digital inclusive finance has a more significant inhibitory effect on inefficient investment. This study expands the research on inefficient investment in private enterprises from the dynamic perspective of the enterprise life cycle, and provides further evidence for digital inclusive finance to promote the development of the private economy.