Piezoelectric thrust eccentricity measurement device is developed in the laboratory as the research object. The characteristic curves of the measuring device are obtained by hammering. Based on nonlinear modal analysis method

modal parameter identification program is worked out

and the theoretical dynamic response transfer functions in three directions of the measuring device are obtained. The identified theoretical transfer function Bode diagram is in good agreement with the amplitude and phase frequency characteristic curves obtained experimentally

and the correctness of the theoretical transfer function is verified. By using the transfer function

can be obtained relationship between the natural frequencies of each order and each link of the measuring device

and provide a strong basis for finding the weak links and improving the natural frequencies of the devices.