Objective To explore the mental health status and the relevant influencing factors of the resident standardized trainees, and to provide reference for the psychological intervention. Methods All the resident standardized trainees in a first class of the third grade hospital in Sichuan from July 2012 to August 2015 were investigated by the questionnaire including symptom checklist 90, demographic characteristics and work condition. Results The detection rate of psychological problem among resident standardized trainees was 24.7% which was higher than the general population. The analysis of logistic regression showed that the training grade, identity, work time and working achievement were the main factors related to psychological problems. Conclusions The psychological problems of resident standardized trainees were prominent because they are in a transformation stage from medical students to clinical doctors. The related department should pay more attention and take measures to improve the resident standardized trainees’ mental health.