The state comprehensively promotes the development of the digital economy, this paper regards the state ownership in private enterprises as an important resource provision and governance mechanism, using the data of private enterprises listed in A-shares from 2013 to 2020, and studies the impact of state ownership on corporate digital transformation. The empirical results show that the state ownership can significantly promote the digital transformation of private enterprises. After classifying the background of state ownership in private enterprises, the state ownership as a strategic investor can better promote the implementation of its digital transformation strategy, while the role of state ownership as a financial investor is limited. Moreover, the state ownership plays a more significant role in promoting the digital transformation of private enterprises in cities with better business environment.