Based on Mohr-Coulomb and modified Drucker-Prager constitutive model

the inversion method of mechanical parameters of similarity model is performed using digital speckle correlation method and finite element method (DSCM-FEM). The similarity model test is carried out

the digital speckle correlation method is used as the experimental observation method

the surface displacement field is analyzed as the measured value during the loading of the model

and the displacement field obtained by the finite element method is used as the simulation value to construct the inverse problem model. The mechanical parameters of similar models are reversed by the optimization algorithm based on the Mohr-Coulomb and the modified Drucker-Prager constitutive model respectively. The test results reveal that the measurements and simulation displacements in the speckle area obtained by the proposed DSCM-FEM mechanical parameter inversion method match both numerically and regularly. The inversion constitutive model based on the modified Drucker-Prager model has higher inversion accuracy.