Abstract：The salt formation is regarded as Maxwell model，and a viscous elastic mechanical model for plane strain features is established. With the analysis and calculation of the external load acted on casing due to salt formation creep under the in-situ stresses，the variation laws of the external load are achieved. The program of finite element method has been established with friendly interface，and the detailed calculation step and formula deduce are presented. Finally，the examples of external load due to the salt creep in the tertiary of Yingmaili oil field have been performed under heterogeneous and homogeneous in-situ stresses. The results achieved in this study may offer reference to the casing design，and provide quantitative and referential evidence for practical engineering cases.
