The paper conducts a comparative analysis on public health information service of domestic and foreign libraries based on relevant theories of comparative librarianship, finds that there is a large gap between public health information service of domestic and foreign libraries, which foreign theoretical study and practical development are more mature, service items are diversified, and users' type are more extensive and diversified while corresponding aspects in our country need to be strengthened. This study is expected to provide references for the practice of public health information service in various libraries in China.