Cell-to-cell communication is essential for the organization, coordination and development of multi-cellular systems. Intercellular communication and substance exchange are important links in the development, tissue repair and cell survival of multicellular organisms. Recently, it has been found that tunneling nanotubes (TNTs) connections are formed between cells for long-distance communication. TNTs are long cytoplasmic bridges that enable long-range, directed communication between connected cells. The proposed functions of TNTs are diverse and not well understood. It has been shown to include that there are considerable differences in the structure, formation process and functional properties of TNTs in cells of different types. Recent progress has been made in this new research field. However, the exact role of TNTs for intercellular communication and their impact on diseases are still uncertain, further research is urgently needed. The combined data from numerous laboratories indicate that some TNTs mediate a long-range communication to coordinate metabolism and signaling. This paper aims to describe the structure, morphology, characteristics and function of TNTs, the formation mechanism of TNTs and the application prospect of TNTs in disease transmission and disease treatment, and discusses the research advances of TNTs-mediated electrical coupling.