With increasingly blurred occupational boundaries in the digital age, technical students face the contradiction between cognitive lock-in of “professional relevance” and the surge in cross-border demand. Based on Career Construction Theory, this paper constructs and verifies a four-stage guidance model of “cognitive deconstruction—advantage identification—narrative reconstruction—path creation” through a qualitative case study of undergraduate-upgraded students majoring in computer science. The research finds that through narrative intervention, the model can effectively guide students to break disciplinary identity lock-in and realize the creative transformation of professional abilities into composite capital. This paper further refines the three-dimensional mechanism of narrative reconstruction, providing an operable, practical path for the transformation of employment guidance for technical majors from “job matching” to “career construction”.