This review focuses at reviewing the progress of brain-computer interface techniques that have been developed over the past several decades. In the process of translating research achievements in brainmachine interfaces into clinical medical devices, new challenges will be encountered. so the characteristics of electroencephalogram, electrocortical graph, and intracortical electrical signal commonly used in braincomputer interfaces are introduced at first. Afterwards, the decoding capability and the bidirectional closedloop of information, the stability and biocompatibility problems of designing commercial brain-computer interface products are all analyzed. Finally, the synergistic development issues of policy, funding, and technological roadmap in the industrialization process of the transformation of implantable brain-machine interfaces into medical devices are briefly reviewed.