The role of new media in emergency management has attracted growing attention;however,comparative studies across different earthquake events remain limited. This study takes the 2025 M6.8 Dingri earthquake in Tibet,the M4.8 Yongning earthquake in Ningxia,the 2024 M4.7 Feidong earthquake in Anhui,and the M7.1 Ushi earthquake in Xinjiang as case studies. Based on Weibo data,it analyzes differences in the dissemination of earthquake-related information on social media during the 72 hours following these events and explores their policy implications. the results show that: (1)higher-magnitude earthquakes generate greater public attention in the initial stage,whereas subsequent attention is strongly shaped by the extent of disaster losses; (2)in moderate earthquake scenarios,public attention tends to shift from immediate disaster impacts to aftershock developments and regional risk assessment,with authoritative information released by earthquake agencies playing a more prominent role; (3)public emotional structures differ markedly across earthquakes of different magnitudes,and in moderate earthquake contexts,negative emotions more closely reflect cognitive responses to uncertainty surrounding subsequent seismic risks;and(4)the spatial dissemination of earthquake-related information generally follows a diffusion pattern from nearby to more distant areas,while economically developed provinces consistently exhibit higher levels of attention to such information. Based on these findings,this study suggests that the content structure of post-earthquake information dissemination should be dynamically optimized according to earthquake magnitude and post-event stage.