Abstract: The crystal structure and grain evolution process of PbTiO₃ perovskite under low temperature conditions were studied using transmission electron microscopy. The results show that under low temperature conditions, there was no significant phase transition in PbTiO₃ perovskite. Under electron beam irradiation conditions, PbTiO₃ crystals exhibited fine－grained phenomena, indicated that the electron beam had an inducing effect on their structural changes. At room temperature and low temperature, PbTiO₃ crystals did not produce dislocation defects, and the low temperature environment slowed down the grain refinement process. The effect of electron irradiation increased the surface energy of materials, led to a decrease in grain size and resulted in the phenomenon of fine crystallization.