Message structure and types have different effects on the dissemination of health information, thus influencing the persuasiveness of individuals' health behaviors. This study used message framing effect of HPV vaccination in online health communities, combined with the mediating effect of message credibility, to explore its impact on college students' attitudes and intentions to receive HPV vaccine (free & paid). The design method of quasi-experiment was used and 324 undergraduates were recruited from two universities. Through questionnaire survey, the research results showed that: (1) compared with the gain-framed message, the effect of loss-framed message will lead to more favorable attitude, intention of HPV vaccination. (2) loss-framed message was more credible to college students, and message credibility plays certain mediate role in the attitude and intention in free vaccination, but not in paid vaccination. The results of this study provide a basis for understanding the differences in the impact of health message framing on attitudes and intentions of HPV vaccination. At the same time, relevant health information services should pay attention to the influence of message framing and message credibility on users' health behaviors, so as to promote health development and enhance health awareness.