Since the first China youth volunteer service project contest (CYVSPC) in 2014, a large number of project related data have been accumulated. These data describe the development of volunteer service and are rich in valuable historical experience. Based on the data of the 5th CYVSPC, this study aims to explore the relationship between the external characteristics of volunteer service projects and the comprehensive evaluation of project quality. The multiple linear regression model was used to analyze the relationship between the characteristics of 984 volunteer service projects with high data integrity and comprehensive evaluation. The results show that the external characteristics have a great impact on the evaluation of volunteer service projects. The number of volunteers, the expenditure of volunteer service projects, and the time of project establishment can explain 47.9% of the evaluation results of volunteer service projects. The healthy development of volunteer service projects should pay more attention to the improvement of volunteer recruitment and training, leaders' academic qualifications and external cooperation.