Abstract: The honeycomb panel, due to its high specific strength and stiffness, is widely used in aeronautical, ABSTRACTS OF THE PRESENT ISSUE astronautical and other fields. The equivalent material parameters are calculated using the sandwich equivalent method, The finite element model (FEM) is set up in MSC.Patran to calculate the first order frequency of the honeycomb panel, which is optimized in Nastran by analyzing the design variable and the objective function, and the optimized result is used to confirm the equivalent modulus of elasticity in shear, which is used to recalculate the first order frequency of the FEM, then the FEM of the honeycomb panel is updated based on the test result. The error between the calculated and the test results is greatly reduced, which shows the validity of the model updating.