Aluminum film was prepared using magnetron sputtering deposition process on depleted uranium surface. The interface reaction between aluminium and uranium was investigated using in-situ X-ray diffraction at high temperature. The reaction product and the changes with temperature and time were researched and discussed. The experimental results indicate that there are absent any of intermetallic compounds in the original sample, and the interface reaction occurs and the intermetallic compound UAl₃ forms when the temperature is higher than 335 °C. The dynamics of surface reaction is in accord with nucleation-growth mechanism. It is interesting that the diffraction peak’s intensity of UAl₃ decreases with the increasing of temperature and disappear at 600°C, which is analyzed and discussed in this paper.