In tandem with internet development and widespread social media use, e-health communities have begun to emerge in recent years. These communities allow doctors to access forums anywhere, anytime, seek or exchange medical information online, find literature, and so on. This is convenient and can solve some problems for doctors while also promoting doctor communication. This study collected and collated 102 doctors in the "Lilac Forum" and used social network tools to quantify the overall network density, centrality, core-periphery structure, and structural hole indicators of doctors' information exchange from a social-capital perspective. The results showed that the frequency of interaction between doctors differed because of differences in the identities and participation of doctors in the e-health community. The density of the doctors' information dissemination network (0.228) and network cohesion (0.610) were relatively high. Thus, the doctors were more closely connected, and information was easily spread. At the same time, doctors with higher professional titles had obvious location characteristics, familiarity and trust, and high levels of reciprocity. They could obtain redundant information in the network and were more likely to influence the behavior of other doctors. This study's findings provide support for improving information exchange among doctors in e-health communities and improving the service levels of the platforms.institutions, and medical practitioners [7]. Forums such as Lilac (www.dxy.cn/bbs) and Love Love Doctor (bbs.iiyi.com/) provide medical information and services to many doctors. However, there are still relatively few active users in medical forums [8], which means the acceptance level of e-health communities is still lacking. Therefore, it is important to explore the information exchange behaviors of doctors in such communities to promote the service level of e-health communities.The e-health community is an electronic information platform where doctors can exchange academic, basic medical, and other information. In e-health communities, doctors can access forums anywhere, anytime, seek or exchange medical information, find literature, and so on. At the same time, doctors can also post comments and questions on the forum and communicate with others. This is convenient and can solve some problems for doctors. If a doctor's area lacks the advanced medical resources and medical resources, and a patient requires advanced treatment, the doctor can access relevant advanced medical information in a forum. Then, the patient can be better prepared for the advanced treatment before the referral, which can increase cure rates [9]. E-health communities also can break the limitations of time and space and help doctors obtain professional knowledge from other doctors at different levels, which can reduce imbalances in medical resources [10]. Although such advantages indicate that e-health communities have good prospects, some shortcomings still exist. First, users of the Lilac forum are independent...