Objective To explore the reshaping effect of Generative Artificial Intelligence (GenAI) on the educational ecology of nursing master′s postgraduates, and construct dual-core model of human-machine collaboration empowered by GenAI for nursing education, and to provide a reference for the education of nursing master′s degree candidates. Methods From June to September 2024, adopting the grounded theory paradigm, semi-structured interviews were conducted with 25 nursing postgraduates and 3 supervisors from 3 universities in Northeast China. Through three-level analysis including open coding, axial coding and selective coding, core categories were extracted and a theoretical model was constructed. Results Four core categories were identified:the reshaping of learning patterns, the bidirectional evolution of nursing professional competence, ethical and psychological tensions in human-machine interaction, and teaching reform and adaptation. On this basis, the core category of dual-core model of human-machine collaboration empowered by GenAI for nursing education was refined. The model demonstrated that the essence of educational transformation lay in two interrelated cores:the student competency development core andthe teaching system responsiveness core, which realized dynamic coupling and collaborative evolution through the tension-regulation hub (ethical conflicts, trust fluctuations, emotional experiences). Conclusion This model provides a theoretical framework for nursing educators to understand the GenAI-empowered human-machine collaboration mechanism, and offers practical pathways for postgraduate competence cultivation, hierarchical teaching intervention and ethical conflict resolution.