Abstract: Flexible printed circuit board is a kind of circuit board with good flexibility and high reliability,which is based on polyimide or other dielectric materials,and made of conductor materials. On the basis of understanding the relevant theories of flexible circuit board structure and random vibration,the finite element simulation model of flexible circuit board structure is established. The mechanical characteristics of flexible circuit board structure under random vibration are analyzed by using COMSOL Multiphysics,and the dynamic characteristics of the flexible circuit board are summarized,which lays a foundation for suppressing the vibration behavior of flexible circuit board.