Dual-arm collaborative robots are designed to achieve refined and cooperative operations in complex environments through human-like dual-manipulator configuration and collaborative control strategies. To systematically sort out the research progress and technical challenges in this field, a comprehensive overview of the key technologies and development trends of dual-arm collaborative robots was conducted. First, the development history, core characteristics and typical application scenarios of dual-arm collaborative robots were summarized. Then, focusing on six key technical fields, namely mechanical structure design, actuation system, motion trajectory planning, multimodal perception, human-robot interaction and control system, the advantages and limitations of existing methods for these technologies were analyzed in depth. Finally, combined with the two major development trends of intelligence and generalization, the main research directions were sorted out. This review provided a systematic theoretical reference for the technical research and system development of dual-arm collaborative robots, and helps promote their practical applications in intelligent manufacturing, medical rehabilitation, home services and other fields.