Under the current setting of a booming digital economy, digital transformation (DT) has become the only strategy available to enterprises for their development; however, it has also become a common concern in domestic and foreign academic circles. Focusing on the specific process of enterprise DT, this study builds a theoretical research framework that comprises input (I)–process (P)–output (O), and creatively divides process into three evolution stages (i.e., informatization, datafication, and intelligentization) in a dynamic manner. It selects Ping An Group, Suning Group, and Midea Group for case analysis. Through a dynamic comparison of the DT processes of the three enterprises from different fields, this study probes into the driving elements of their DT at different stages. The following differences were found: crucial driving elements originate from the technical and environmental levels during the informatization stage, the technical and participant levels during the datafication stage, and the technical and organizational levels during the intelligentization stage, with the technical driving element running through all the stages of enterprise DT. From the perspective of multiple cases, this study discusses the driving elements of enterprise DT and proposes a theoretical framework of dynamic evolution as a theoretical reference for practices in enterprise DT.