Abstract: With the rapid development of the digital economy, more and more enterprises have begun to carry out digital transformation. However, most traditional enterprises are facing many difficulties in the process of transformation. Therefore, in order to find out how enterprises can effectively repositioning themselves and promote the improvement of their core competence in the digital transformation, this study takes four representative enterprises as the research objects to conduct a multi-case qualitative research based on grounded theory. It is found that in the digital transformation, the effective repositioning of enterprises is based on how to best leverage the resource advantages of their original positioning and establish new business scopes that are most advantageous, transferring or expanding their positioning in both the industrial chain and segmented markets. In line with this, the core competencies of enterprises also exhibit the pattern of "developing and discarding", as enterprises develop their core competence in such a manner as to integrate, absorb, digest and integrate new advantageous resource capabilities on the one hand, and weaken or even give up some of the constituent elements of the original core competence on the other. Furthermore, it is found that the digital capabilities formed by the absorption and integration of digital technology or resources by enterprises promote the effective and smooth "developing and discarding" evolution of core competencies through four ways:adding new value links, strengthening original advantage capabilities, promoting resource integration, and improving knowledge sharing, thereby helping enterprises quickly establish new advantages in digital transformation. This study reveals how enterprieses' core competence gets upgraded through developing and discarding, improves the theories of repositioning and core competence transformation, and provides a new perspective for the theory of resource orchestration.

Key words: digital transformation, repositioning, core competence, developing and discarding, digital competence