Abstract: Satellite Internet of things (SatIoT), positioned as the core evolutionary direction in sixth-generation (6G) mobile network architectures, is establishing a globally seamless ubiquitous IoT connectivity framework with integrated service capabilities through space-terrestrial collaborative networking technologies. Multiple access technology, as a key technology supporting dynamic access for large-scale users in SatIoT, primarily aims to achieve on-demand, orderly, and reliable concurrent access services for massive user terminals through intelligent allocation mechanisms of wireless resources. We review the evolutionary trajectory of ALOHA-based multiple access technologies, categorize existing access technologies into two major technical lineages—slotted random multiple access and unslotted random multiple access—from the perspective of time constraints on data transmission, and conduct a classified analysis of their technical characteristics, delving deeply into the physical layer implementation principles and protocol properties of various technical approaches. Regarding the direction of convergent innovation, we summarize the design paradigms and research achievements of novel hybrid random multiple access technologies, and collate cutting-edge research progress from dimensions such as protocol architectures, spectrum sensing, and service modeling. Finally, we identify future technological directions and development trends in areas including on-demand access control, simplify random multi-access, multi-access edge computing (MEC)-enabled random multi-access, and data-model co-driven model and scenario verification.