Abstract: Tritium is the key nuclear fuel in nuclear fusion reaction, and the metal tritides are important functional materials in the fields of national defense and nuclear fusion energy. The generation of helium atoms during the decay of radioactive tritium atoms and their evolution during aging seriously affect the macroscopic properties of metal tritides. The formation and residence of helium bubbles will affect the tritium storage properties of metal tritides. The research on the helium bubble growth mechanism in the metal tritide has attracted more attentions. Due to the radioactivity of tritium atom and the lack of microscopic analysis techniques for the light element atoms of tritium and helium, the establishment of helium bubble growth model has been in phenomenology theory for a long time. In recent years, with the progress of electron microscopic analysis technology, new technologies for the accurate analysis of helium bubble information have been proposed, which enhances more accurate and deeper understanding on the microscopic mechanism of helium bubble growth in the metal tritides. This paper will first introduce the main achievements of the researches on the microscopic mechanism of helium bubble growth in metal tritides, and then focus on the new electron microscopic analysis technologies and its research progress. Finally, the research trend of the microscopic mechanism of helium bubble growth is prospected.