Visual complexity plays a crucial role in consumer purchase behavior. However, existing research on background complexity in live streaming commerce is limited. Drawing on the stimuli-organism-response (S-O-R) theory, this study aims to explore the relationships between live background complexity, consumers’ emotion and purchase intention. A 3×2 between-subjects online experiment was developed to collect the participants’ related emotion and intention data. The results primarily indicated that consumers’ emotions (i.e., pleasure and arousal) can be evoked by the visual complexity and further positively influence their purchase intention. Consumer emotion shows a nonlinear mediation effect between live complexity and purchase intention. The moderator role of gender in the relationship between complexity and consumer emotion was also examined. The result revealed that the difference between men and women only exists in the pleasure dimension.