Purpose/significance To explore strategies for improving the health information service mode of public libraries, so as to realize the transformation of users from passive health to active health. Method/Process According to the influence factors such as user’s health information behavior, expected status and health information concern degree, the public library health information service mode is constructed by using 5W1H analysis method. Result/Conclusion The health information service mode of public library is constructed from 5 aspects:“subject”“content”“object”“method” and “place”.