China’s foreign medical aid teams are vital to health diplomacy, with local governments playing a pivotal role in discursive mediation. This study analyzes official reports on Ningxia Hui Autonomous Region’s medical aid teams to Benin from 2006 to 2024, employing Discourse-Historical Analysis (DHA) to examine how local media construct legitimacy narratives. Diachronic analysis reveals a shift from emotionally charged “humanitarian redemption” to strategic narratives of “technological empowerment” and “global governance partnership.” Through referential, predicational, and argumentation strategies, local media utilize the “recontextualization” mechanism to translate national diplomatic strategies into localized practices. The study highlights “technological governance” as an emerging soft power resource and provides empirical insights into vertical narrative transmission at the sub-national level.