In order to discuss the deformation properties of the soft rock, based on the specific nuclear project located on the soft rock, a three dimension finite element model of Nuclear Island foundation was generated and the rheological constructive model which is suit for the soft rock was developed in this paper. This constructive model was embedded in software FLAC3D. The comprehensive assessment model of the attribute recognition based on the entropy weight of sensitivity was adopted in the sensitivity analysis for the geotechnical parameters of soft rock. And the inversion calculation applying the uniform design –advanced genetic analysis-neural network method was also carried out. Based on the monitoring data, the new geotechnical parameters used in elastic-plastic model and viscoelastic-plastic model were obtained through inversion calculation. Then the settlement analysis was carried out using the numerical method based on the optimized parameters. The settlement prediction also can be produced. The method used in this paper can be adopted in the settlement calculation of soft rock in the similar projects.