Abstract: The seismo-ionospheric monitoring technology has been quickly developed in recent years, which provides new ideas and techniques for short-term and imminent earthquake prediction. The multi mechanisms about sphere coupling processes related to earthquakes are reviewed and summarized since this century. Three channels with realized digital model are introduced, including overlapped DC electric field model, acoustic gravity wave and electromagnetic wave propagation model. Compared with the actual observations, the contradiction and deficiency in the models are analyzed. Finally, based on the existing observation systems, the main ideas and research directions in the seismo-ionospheric coupling mechanism in the future are discussed.