Based on transient finite element method (FEM) and displacement aging coefficient, a method was  proposed to obtain the influence of the rheological properties of soft soil on engineering construction. The transient soil displacement was simulated using the FEM simulation method. According to analysis of soft soil from displacement timeliness, its transient displacement could be changed into long-time displacement with rheology. And the displacement aging coefficient was calculated from triaxial rheological test of soft soil and the most negative time in the site. So this coefficient can reflect the rheological unstable condition of soft soil. A case of excavation simulation of the South East Outer Ring Road Station in Ningbo was conducted using this method. The calculated displacement result of soft soil agrees well with the on-site monitoring result.