The relationship of geometry parameters, specific stiffness, surface figure and natural frequency was investigated based
on modified Gibson theory, sandwich theory, Hoff theory and vibration theory. By theoretical analysis and finite element
method, we demonstrated the geometric parameters had non-linear influence on dimensionless specific stiffness in
different directions with the honeycomb core was equivalent as modified solid material. Approximate expressions of
deformation, natural frequency and geometric parameters were obtained. The results showed the optimal solidity ratio
and face plate thickness ratio were in the range of 0.03 ~ 0.1 and 0.02 ~0.05, respectively.