The electromagnetic environment serves as the fundamental medium for radio wave propagation and profoundly influences the operational efficiency of global information infrastructure systems, including communications, navigation, and security.The research focused on electromagnetic environment sensing constellations developed within the commercial spaceflight sector and summarized the evolutionary development of electromagnetic environment sensing constellations through three major phases: the military electromagnetic reconnaissance–dominated era, the stage of global collaborative competition, and the phase of commercial and national co-leadership. Representative constellations and their functional characteristics were outlined for each phase.Current in-orbit constellations were categorized into four primary types—propagation environment sensing, broadband RF signal sensing, typical operational signal sensing, and multimodal integrated sensing—and their functional characteristics, core capabilities, key technologies, and application scenarios are analyzed.Ongoing development trends are identified in commercial space-based electromagnetic environment sensing toward space–ground system integration, multi-satellite network collaboration, multimodal fusion, and real-time artificial intelligence integration.