With the rapid development of e-commerce live streaming, streamers play a crucial role in consumers' shopping experience and decision-making. In this context, humor has gradually attracted widespread attention in the field of marketing as a communication strategy to enhance interaction between streamers and consumers. According to social exchange theory, this study specifically explores the differing impacts of e-commerce streamers' humor styles on relationship quality, as well as the positive effect of relationship quality on consumers' repurchase intention. Data were collected via an online survey with 519 valid responses, and structural equation modeling (SEM) was conducted using AMOS. The results reveal that affiliative humor significantly enhances consumers' trust (beta = 0.22, p < 0.001), which positively affects satisfaction and commitment, ultimately increasing repurchase intention. In contrast, aggressive humor undermines trust (beta = -0.63, p < 0.001), leading to lower repurchase intention. This study provides theoretical support for e-commerce streamers to enhance consumers' repurchase intentions by increasing the use of affiliative humor and reducing the use of aggressive humor.