A time-domain test method for nonlinear damping of fiber reinforced composite thin plate based on nonlinear squeezing transform was proposed. The analytic signal was constructed based on the nonlinear squeezing transform

and the expression of nonlinear damping of the composite structure system was derived

so that the theoretical principles of acquiring the nonlinear damping parameters from the time-domain test view could be clarified. Then

the Matlab algorithm was written and numerical example was used to prove the correctness of the algorithm. The reasonable and standard test procedures were summarized and applied to real measurement of TC500 carbon fiber/resin composite thin plate. It was proved that the proposed method can effectively obtain its damping parameters in different decay time

thus it can be used to quantitatively evaluate nonlinear damping characteristic of composite structure under different excitation amplitudes and frequencies.