Based on the physical mechanics experiments and a series of three static triaxial test of marine soft soil,we fit the mean stress and the generalized shear stress value of marine soft soil,consider that state line of marine soft soil is hyperbolic,take the modified Rhodes stress angle into the model,and improve the Cambridge model to make it more responsive to the static characteristics of marine soft soil.The practice shows that the modified Cambridge model of marine soft soil effectively simulates the stress-strain characteristics of marine soft soil,and shows the nonlinear characteristics of the soft soil and the characteristics of the plastic flow.Based on the modified Cambridge model of marine soft soil,we numerically analyze the foundation settlement of sea dike project based on marine soft soil,and verify the applicability of the modified Cambridge model of marine soft soil by the calculation result.