Abstract: This study explores the evolving role of social media trending topics in the governance of cyberbullying within digital societies, aiming to uncover their dynamic relationship and propose enhanced regulatory mechanisms. By analyzing trending lists as platforms for information aggregation, this study highlight their dual function in both spotlighting critical social issues and inadvertently amplifying cyberbullying incidents. This investigation reveals a shift in platforms' roles, transitioning from traditional "gatekeepers" of information to contemporary "negligent actors", and in some cases, potential "perpetrators" of harm. Through case studies, this study identify six manipulative strategies employed in these contexts: Naming control, rumor propagation, opinion guidance, detail amplification, scapegoating, and suspicion engineering. These tactics not only exacerbate the spread of cyberbullying but also intensify harmful interactions within public discourse. To address these challenges, this study propose a series of countermeasures, including strengthening the enforcement of anti-cyberbullying legislation, improving platform governance protocols, and advancing user media literacy initiatives. These measures are designed to foster healthier digital ecosystems while offering practical guidelines for optimizing discourse governance in the algorithmic age.