This qualitative study explored: (a) How do the three English-Education-major (EE hereafter) undergraduates perceive their academic self-efficacy change experiences over the first two years after major transfer? (b) What are the personal and social factors that prompt their academic self-efficacy change? Data was collected from three EE students at S University in S city, China. Data sources include semi-structured interviews, reflections, and observation notes. Data analysis uses qualitative content analysis, adopting an inductive approach to allow themes to naturally emerge from the data. Findings reveal that participants experienced academic self-efficacy changes through continuous and uneasy processes. Significant changes were noted in the participants’ academic self-efficacy. Key personal factors, including mastery experiences and physiological/emotional states, along with social factors, including verbal and social persuasion and vicarious experiences, were found to substantially influence self-efficacy. In light of the above findings, practical implications were proposed for EE programs and program developers from the three aspects: creating opportunities for mastery experiences within EE programs, incorporating elements of social persuasion and vicarious learning, and integrating modules focused on managing anxiety and fostering resilience. Limitations of this study and recommendations for future research were discussed.