Under the condition of noise measurement, a method of parameter identification based on the extended state observer(ESO) is discussed as well as its application. The influences of measured noise to the states of ESO are analyzed by simulations and experiments. To improve the identification results in the practical systems, an integral filter is introduced to suppress the noise with low contamination to the observed state. This method can well handle the non-uniformly periodically sampled data, and can be applied to identify parameters of irregular sampling system. Finally, two kinds of practical processes are realized in an adjustable experiment system, and the effectiveness of the proposed method is validated via two experiments.