The present invention discloses a dynamic signal parameter identification method and system. The method comprises: according to a dynamic signal current waveform envelope curve shape, establishing a current mathematical model; determining the type of the current mathematical model according to a first-order derivative value, a second-order derivative value and the ratio of the first-order derivative value and the second-order derivative value; according to the determined type of the current mathematical model, selecting a predictive algorithm aiming at the determined type of the current mathematical model, employing the predictive algorithm to perform predication of parameters of an envelope portion and a direct current portion, and obtaining approximate values of parameters of the envelope portion and the direct current portion; and according to the approximate values of the envelope parameters, employing the difference algorithm to identify the envelope parameters, and obtaining the accurate values of the envelope parameters and direct current components. The dynamic signal parameter identification method and system employ the difference evolution algorithm to play a good effect on the global searching optimization of the envelope parameters, and are faster in convergence speed and higher in precision.