<p>As practice changes and theory develops, the significance of control-based formal leadership models has been weakened, and horizontal informal leadership models have gradually attracted researchers’ attention. In this context, leadership emergence has been increasingly emphasized as a form of informal leadership. Existing research on leadership emergence has predominantly focused on its antecedents and positive outcomes, while discussions regarding its negative consequences remain largely at theoretical speculation. Meanwhile, prior studies on the negative effects of leadership have mainly concentrated on formal leadership positions. However, leadership emergence is fundamentally distinct from formal leadership due to its lateral and spontaneous characteristics, rendering the sources of its job demands unclear<b>.</b>In view of this, drawing upon adaptive leadership theory and the Job Demands-Resources (JD-R) model, this study explores the negative effects of leadership emergence from an outcome perspective. Using a three-wave data collection method (leader ratings, peer ratings, and self-ratings), we analyzed 351 matched employee responses from 70 teams. The results indicate that: First, leadership emergence leads the focal employees to experience emotional exhaustion by exacerbating their role ambiguity. Second, leadership emergence leads the focal employees to experience emotional exhaustion by increasing their workload. Third, advice network density in teams plays a moderating role between leadership emergence and role ambiguity, as well as between leadership emergence and workload. Role ambiguity and workload caused by leadership emergence are weakened in teams with a higher density of advice network. This study not only provides a more comprehensive perspective on the effects of leadership emergence but also inspires organizations to take a dialectical understanding of leadership emergence.</p>