Three-dimension CAD model of an operator cabin was built with CATIA software. The model has been inputted into ANSYS through an interface program. After modified properly, the model was meshed. The ANSYS solver was launched to calculate the model in order to get the modal parameters. Then, “design parameter modifying method” of structural finite element model was introduced briefly. On the basis of that, the finite element model of the operator cabin was modified dynamically. The calculation and analysis result showed that the finite element model modified with this method was able to reflect the structural dynamic characteristics accurately and that this method possesses excellent reliability.