In light of the existing gap between the need for efficient coordination in major earthquakes—from the emergency initiation phase to the emergency rescue phase—and the current operational realities, this study examines the development of an emergency command and coordination information service support system. Drawing on analyses of central emergency operation commands in organizations and countries such as the United Nations, the United States, Japan, and Russia, the research investigates their institutional structures, coordination mechanisms, and post-disaster information flows. Furthermore, case studies of major seismic events—including the 2008 Wenchuan(M8.0), 2010 Yushu(M7.1), and 2013 Lushan(M7.0) earthquakes in China, as well as the 2011 East Japan(M9.0) earthquake in Japan—are compared to identify strengths and shortcomings, particularly in information sharing among command headquarters. The findings highlight persistent issues in cross-agency, cross-level, and cross-regional communication. To address these challenges, the paper proposes a set of countermeasures, including establishing a disaster coordination system, developing standardized emergency information protocols, and creating specialized information centers or dedicated information teams. These measures aim to enhance information interconnectivity and coordination, thereby strengthening the information support system to improve both preparedness and response in the context of major earthquake disasters.