Numerous efforts have been made to fabricate Li2TiO3 tritium breeding ceramics with satisfactory density and mechanical strength while maintaining a fine grain structure. In this study, high‐energy ball milling was performed to promote grain refinement and amorphization of TiO2 and Li2CO3 powders, thereby preparing Li2TiO3 ceramic at a reduced sintering temperature. In the presence of high‐energy ball milling, powder mixtures with particle sizes of 24–29 nm were obtained, and the formation of β‐Li2TiO3 occurred at 400°C. The relative density and crushing load of Li2TiO3 ceramic pebbles improved as the ball‐to‐powder ratio and milling time increased. The Li2TiO3 ceramic pebbles sintered at 900°C exhibited a tiny grain size, satisfactory relative density (89%), and excellent crushing load (121 ± 13 N). The results also demonstrated that Li2TiO3 ceramic possessed the maximum thermal conductivity and ionic conductivity under the conditions of a 20:1 ball‐to‐powder ratio and 20 h milling time, that is, 5.028 W/m·K and 1.87×10−2 S/m at room temperature. Overall, the high‐energy ball milling process has shown advantages in the fabrication of tritium breeding ceramics with fine‐grained structure and excellent comprehensive performance.