Background The undergraduate program of psychiatry has been widely established in recent years to improve the education and recruitment of psychiatrists in China. We aim to investigate the career choice of medical students majoring in psychiatry in China and the influential factors. Method This multicenter study was conducted in 26 medical schools in China from May to October of 2019. Participants included 4610 medical students majoring in psychiatry and 3857 medical students majoring in clinical medicine. Multivariable logistic regression was used to investigate the influential factors of students’ choices of psychiatry at matriculation and as a career. Results 44.08% of psychiatry majored students gave psychiatry as a first choice at matriculation, and 56.67% of them would choose psychiatry as a career, which was in sharp contrast to the proportion of clinical medicine majored students who would choose psychiatry as a career (0.69%). Personal interest (59.61%), suggestions from family members (27.96%), and experiencing mental problems (23.19%) were main reasons for choosing psychiatry major at matriculation. Personal interest (odds ratio [OR] = 2.12, 95% confidence interval [CI] = 1.87–2.40), experiencing a psychiatry clerkship (OR = 1.99, 95% CI = 1.28–3.08), being female (OR = 1.50, 95% CI = 1.30–1.68), experiencing mental problems (OR = 1.33, 95% CI = 1.28–1.56), and suggestions from family members (OR = 1.25, 95% CI = 1.08–1.46) correlated positively with students’ choice of psychiatry as career. Students who lacked psychiatry knowledge (OR = 0.49, 95% CI = 0.29–0.85) or chose psychiatry because of lower admission scores (OR = 0.80, 95% CI = 0.63–0.97) were less likely to choose psychiatry as a career. Conclusion More than half of psychiatry majored medical school students planned to choose psychiatry as their career, whereas very few students in the clinic medicine major would make this choice. Increasing students’ interest in psychiatry, strengthening psychiatry clerkships, and popularizing psychiatric knowledge are modifiable factors to increase the psychiatry career intention. The extent to which medical students’ attitudes toward psychiatry can be changed through medical school education and greater exposure to psychiatry will need further investigation.