What role do emotions play in state repression? Building upon ethnographic observation in one Beijing petition bureau, this paper explores the emotional labour performed by grassroots officials to demobilize social dissent. The petition system serves as an official channel through which the Chinese government receives complaints and grievances from citizens. Notwithstanding its institutional inefficiency in addressing petitioners’ requirements, this system plays a critical role in maintaining social stability. I investigate the process by which frontline petition officials manage petitions. I argue that channelling petitioners’ emotions has become one of these officials’ core functions. Petition officials have developed three types of emotional strategies – emotional defusing, emotional constraint and emotional reshaping – to absorb petitioners’ complaints. This study of emotional repression offers a fresh perspective on the affective dimension of contentious politics and also contributes to the theoretical discussion on how authoritarian regimes deal with dissent.