Based on the improvement of transmission electron microscope (TEM), nano fabrication, and film deposition, and with the development of the in-situ liquid TEM and nano characterization platform, various relevant nano researches have been carried in different fields. In this article, the principle, basic design requirements, development and typical preparation technologies of the liquid cell are briefly introduced. Subsequently, the state-of-the-art applications of liquid cell transmission electron microscope in the nucleation and growth of nanoparticles are reviewed. Finally, the opportunities and challenges faced by the frontier development of this technology are also discussed. This article provides constructive discussion about and support for advanced nano characterization technology and precise manipulation of atomic structures.