Digital transformation is reshaping corporate governance and significantly influencing management monitoring， yet relevant research remains limited. It used managerial perks， a common way for managers to capture private benefits， as an example to explore how digital transformation affects the capture of private benefits by managers through its impact on corporate free cash flow. Based on data from listed firms in China， it finds an inverted U-shaped relationship between digital transformation and managerial perks， indicating that as the degree of corporate digital transformation increases， managerial perks first rise and then fall. The analysis of the underlying mechanism showes that digital transformation influences managerial perks by affecting firm free cash flow： there is an inverted U-shaped relationship between digital transformation and firm free cash flow， and free cash flow has a positive impact on managerial perks. The moderating effect analysis reveals that the higher the degree of industry and regional diversification of a company， the stronger the impact of digital transformation on managerial perks. It reveals that digital transformation affects managerial perks through the new mechanism of free cash flow， which offers important insights for companies to prevent managers from capturing private benefits during the digital transformation process.