Although digital transformation is usually associated with technology, it is fundamentally a marketing concept. However, the role of marketing departments in enterprise digital transformation has been rarely studied. Based on the data of Chinese Shanghai and Shenzhen A-share listed firms from 2011 to 2020, this study examines the mechanisms underlying the impact of sales force investment on enterprise digital transformation. The empirical study indicates that: firstly, there is an inverted U-shaped relationship between sales force investment and digital transformation; secondly, the process analysis of digital transformation indicates that the inverted U-shaped relationship between sales force investment and digital transformation will be weakened when the government digital attention is low, marketing absorptive capacity is high, financial flexibility is high; thirdly, the impact mechanism reveals that the relationship between sales force investment and digital transformation is partial mediated by corporate competition orientation and risk-taking level. This paper provides new insights for understanding the important role of marketing department in promoting the development of digital economy in the digital era.