As a new form of poverty governance, government officials’ livestreaming e-commerce of agricultural and sideline products has been booming since the outbreak of the coronavirus disease (COVID-19) in 2019. However, exploring the determinants of consumer purchase intentions in the context of government officials’ livestreaming is still limited. Drawing on the stimulus–organism–response (S–O–R) framework, this study develops a research model to examine the effect of platform factor (information quality), user factor (bullet screen mutuality), and streamer factors (streamer trustworthiness, streamer expertise, and streamer responsiveness) on perceived information usefulness and arousal, which in turn affect purchase intention. This study also integrates impulsiveness as a moderator. We use structural equation modeling to analyze 430 samples. Our results show that perceived information usefulness and arousal have a significant positive influence on purchase intention. Moreover, impulsiveness moderates the relationship between perceived information usefulness and purchase intention and between arousal and purchase intention. Livestreaming features and streamer characteristics can activate these two mechanisms. This study provides theoretical contributions to livestreaming and the S–O–R literature, as well as practical insights into livestreaming government officials.