Three saints of Avatamsaka—Sakyamuni, Manjusri and Samantabhadra—of Caoxi Temple in Yunnan Province are remarkable wooden statues of the Dali Kingdom (937—1253). They were exquisitely made and show solemn states. In our study, X-ray radiography, a non-destructive technology, was undertaken to investigate the techniques of their manufacture, historical conservation marks and their condition of preservation. The results provide a deeper understanding of the three saints and a considerable reference for the future conservation work. This work also demonstrates that X-ray radiography is a non-intrusive and efficient method for the study of ancient wooden statues of large size.