WeChat official accounts (WCOAs) have emerged as a prevalent medium for information dissemination in Chinese academic libraries over the past decade. This study quantitatively analyzed the whole-year performance of 120 WCOAs from 117 medical college and university libraries, using the WeChat communication index (WCI) algorithm to evaluate communication power at three levels: macro-level accounts, meso-level content themes, and micro-level individual posts. The results showed that 55.6 % of the libraries have activated WCOAs, with an average annual output of 129 posts and 72 broadcasts per account. However, these accounts demonstrated a relatively low average WCI of 249.24, with a small percentage of high-impact posts. A deeper analysis reveals that reading promotion was the overarching theme, and basic library services and digital resource services were frequently highlighted with a high topic communication index. Notable concerns were also identified, including non-audience-centric posting schedules, a disproportionate focus on leisure-oriented content rather than academic support, and a scarcity of original posts. This study provides a snapshot of the developmental stages of WCOAs in Chinese academic libraries from a publication and communication perspective, and also offers pragmatic guidance for their development.