Objective To investigate the current state of mentoring relationship among medical postgraduates, providing insights for optimizing postgraduate mentorship. Methods A self-designed survey questionnaire covered 491 medical postgraduates from grade 2019 to 2021 at an affiliated hospital of a university in Zhejiang Province from March to May 2022, in order to understand the features of their mentoring relationship. Rank sum test is applied to statistically process the survey results. Results A total of 456 valid questionnaires were collected as a result. Out of the participants, 252(55.3%) postgraduates reported communicating with their mentors at least once a week. Furthermore, 389(85.3%) postgraduates were satisfied with the current status of the relationship, and 445(97.6%) mainly focused on academic communication with their mentors. The adequacy of guidance and communication among mentors aged 35 to 45 was 5 (4, 5), which was higher than 4 (3, 5) in the age group of 56 to 60, and the difference was statistically significant (H=3.23, P=0.013). The two primary reasons for the occurrence of guidance problems were identified as mentor being overwhelmed with busy schedules and lacking guidance [338(74.1%)] and students not actively seeking educational support [205(45.0%)]. Effective strategies to improve mentoring relationships included providing more targeted academic guidance for postgraduates [321(70.4%)], encouraging students to be more proactive in seeking guidance from mentors [291(63.8%)], and creating a conductive learning atmosphere through interaction and communication between mentors [318(69.7%)]. Conclusions Medical postgraduates have good communication with their mentors, and the majority were satisfied with the current state of their relationships. However, communication content between them was relatively one-dimensional. Both mentors and postgraduates share the responsibility for problems occurring during mentorship. Improving communication frequency, expanding communication content, strengthening interaction, and creating a good atmosphere were important directions for optimizing mentoring relationship.