Against the backdrop of modernization, exploring the connotation and function of ethnic wedding rituals is crucial for understanding the symbiotic relationship between rural mutual assistance traditions and ethnic cultural inheritance. Taking the three-stage wedding rituals (Xiao Xiangbang, Da Xiangbang, and the official wedding day) of the Ruka branch of the Naxi ethnic group in Wushuwan Village, Sanba Township as the research object, this study adopts participatory observation, in-depth interviews and literature analysis methods. The research finds that the three-stage wedding rituals have distinct functional divisions: Xiao Xiangbang and Da Xiangbang are practical carriers of rural mutual assistance, forming a gradient participation model from kinship to extended kinship and reflecting the logic of the “differential mode of association”; the official wedding day is a concentrated presentation of Sanba Naxi traditional culture, embodying ethnic connotations through elements such as pine gates, traditional costumes and scripture recitation. These rituals also assume the function of intergenerational education, transmitting ethical norms and cultural concepts through oral tradition and ritual practice. The study reveals the dual social functions of the rituals in maintaining rural mutual assistance networks and inheriting Naxi ethnic culture, providing a typical case for exploring the connection between rural mutual assistance and ethnic cultural inheritance in border areas.