In the context of high - quality development，this study aims to enhance the standardized development of medical service quality across multi-campus hospitals. We conducted an analysis on the medical service quality and its influencing factors across three campuses of a top - tier public tertiary hospital. By adopting the SERVQUAL model，we designed a survey based on six dimensions：reliability，assurance， responsiveness，empathy，tangibles，and affordability. Multiple regression analysis was applied to identify the influencing factors of the quality gap in medical services among different hospital campuses. Furthermore，the IPA quadrant chart was used to present patients’expectations and perceptions of medical service quality across various dimensions，reflecting the distribution of importance. The results show that individual characteristics of hospitalized patients affect satisfaction ratings，and there are significant overall differences in medical service quality among different campuses，with considerable variation among 28 specific indicators. The IPA quadrant analysis further indicates that many of improvement priorities are shared across different campuses. The study demonstrates that the SERVQUAL model is applicable for this evaluation research. However，a gap still exists between the current medical service quality provided by each hospital campus and patients’expectations， indicating the need for quality improvement to achieve homogeneous development.