You are asking whether a doctor can become a university teacher if he changes his major. A doctor can be a teacher when he changes his major.

Requirements for university teachers:

1, teacher qualification certificate. This is the most basic requirement. As long as you are engaged in the teaching industry, having a teacher qualification certificate is the most basic stepping stone.

2. Education. Most colleges and universities require candidates to have a master's degree or above, and a small number of positions also require a doctor's degree or above, preferably graduates from prestigious schools or returning doctors.

3. Academic research results. If you want to be a university teacher, the applicant must at least have published academic papers in journals at or above the provincial level, or have some outstanding research results in some industry fields.

4. Work experience. Before applying for a job as a university teacher, you have been engaged in teacher-related work and have a thorough understanding of the nature of teachers' work. If you have no work experience, you should generally start as a teaching assistant first, and then decide whether you are qualified to become a university teacher after your work level and school assessment.

5. Have good physical and psychological qualities. Candidates need to love teaching, have good professional ethics, have a solid cultural foundation, and talk elegantly, which has a good guiding role for students.