Based on the case study method, this study carried out content analysis and statistical analysis of 1000 thematic posts and corresponding reply posts extracted from Baidu breast bar. The analysis focuses on the participation type, participation content and participation preference of users in online health community. This study found that the participation behavior of the healthy community users includes ten types of participation behavior: help seeking, questioning, description, emotional expression, experience description, knowledge sharing, social contact, advertising, and so on. Among them, the number of users involved in questioning, help seeking and description is the largest, and such as experience description, querying, and emotional expression are more likely to cause interaction among other users.