Abstract:Objective：The purpose of the study was to use the Service Quality Gap Model into the field of volunteer service，and put forward the improvement measures and suggestions for medical service by understanding and analyzing the patient satisfaction and service demand. Methods：The SERVQUAL evaluation method was adopted to randomly select outpatients and their families in ina certaingrade-A tertiary hospital in Xuzhou in June 2019 to conduct a questionnaire survey on service quality expectations and perceptions. Then the data is analyzed by SPSS23.0. Results：Patients have higher expectation than perception in the Outpatient Volunteer Service. Among patients' perceptions and expectations of the quality of medical services，patients have the highest evaluation of reliability and the lowest evaluation of empathy. The difference between the guarantee gap of other relatives and friends living with other family status（living with spouse，alone and living with children）is statistically significant（P＜0.05），and the difference between the reliability gap between patients living with children and other patients（living with spouse，alone，living with other relatives and friends）is significant（P＜0.05）. Conclusion：The service quality difference model can be used as an effective method for evaluating the quality of outpatient volunteer service. It can find out the problem of volunteer service quality for relevant management departments of the hospital，and provide a basis for outpatient service managers to formulate management strategies to improve the quality of outpatient services.