Abstract: For computational reliability and strictness of the theory of the plate and the subgrade reaction, first, the attenuate factor of the displacement is corrected for the subgrade out the plate on two-parameter subgrade. Then, Based on the analytical solution of an elastic rectangle plate with four free edges rested on the semi-infinite elastic subgrade, it is proved that the reaction force of the subgrade and the deflection did not possess the relationship of Vlazov’s two-parameter subgrade model by numerical method. Finally, based on numerical computation for a sample problem and comparative analysis of its result, from the bent deformation of the plate, a conclusion is drawn that the attenuate factor given in this paper is suitable, and the computational accuracy is analyzed and given for all sorts of proximate boundary conditions of the plate on two-parameter subgrade.