With regard to platform performance and trust, we study the influencing factors of users’ intention to pay on an online medical service platform. Results of this paper will provide a new perspective for online medical service platform research in the context of the Internet.A questionnaire survey is administered to collect 312 effective sample data, and the data are analyzed by partial least squares structural equation modeling. Results showed that the information quality, system quality, and convenience of the platform significantly affect the perceived benefit (PB) of users. Users’ perceived reliability of the platform significantly positively affects doctor reliability (DR). Users’ PB significantly positively affects their ITP and DR, and DR significantly positively affects the users’ ITP. The misdiagnosis risk positively regulates the relationship between the users’ trust tendency and DR. The timeliness of the response of the platform positively adjusts the relationship between DR and users’ ITP.