Abstract: The index of pressure sensors is determined by corrugated diaphragm on physical level. In order to improve the performance and accuracy of pressure sensors, it is necessary to design and manufacture the corrugated diaphragm with the optimal structure. Based on the finite element method, the working mechanism of corrugated diaphragm in pressure sensors is simulated in this paper. Then the stress and displacement results are obtained, and the calculation method of the corrugated diaphragm stiffness is determined. Then the optimal wave number of the corrugated diaphragm structure could be obtained through changing the wavenumber parameter of the corrugated diaphragm; and the linearity of the stiffness of corrugated diaphragm is verified based on this structure at different temperature. The research results can improve the performance of corrugated diaphragm on structural level. It can also improve the performance of pressure sensors, and provide method reference and theoretical basis for the optimization of other parameters of corrugated diaphragm.