Tunneling nanotubes（TNTs）are intercellular pipe structures formed mainly by actin，which are equivalent to bridges connecting cells. As a newly discovered mechanism of intercellular communication， TNTs realize long⁃distance communication and directional transport of substances between cells. TNTs mediate the transfer of organelles，nucleic acids，small molecular proteins and other substances between cells. TNTs use communication and transportation functions to influence the occurrence and development of neurodegenerative diseases，tumors，cancers and other diseases，and provide some new ideas and new targets for the treatment of related diseases. This review introduces the morphological structure，formation mechanism，formation related regu⁃ latory factors，functions and physiological significance of TNTs.