In order to study the deformation characteristics of the clay core rockfill dam of the Sifangjing water control project in Yichun city during the construction period according to the monitoring data, the deformation characteristics and distribution rules of the main monitoring sections were analyzed. The results show that the dam deformation conforms to the general law of the construction period of the face rockfill dam, whose deformation is small and the construction quality is good. The research results can be used as a reference for similar projects.