The invention relates to a power system dynamic equivalence method based on niche immune algorithm, which comprises the following steps: setting perturbation inside a research system, measuring the dyThe invention relates to a power system dynamic equivalence method based on niche immune algorithm, which comprises the following steps: setting perturbation inside a research system, measuring the dynamic response to call wires of the research system and an external system in the perturbation period, equating the external system connected with the research system into a generator, establishing anamic response to call wires of the research system and an external system in the perturbation period, equating the external system connected with the research system into a generator, establishing agenerator model to be identified, identifying the generator model by using a niche immune algorithm so as to obtain parameters of the generator model, verifying and checking the measured dynamic respogenerator model to be identified, identifying the generator model by using a niche immune algorithm so as to obtain parameters of the generator model, verifying and checking the measured dynamic response to call wires and the identified dynamic response to the generator model under the same excitation, verifying equivalence results and obtaining an equivalence model. The invention identifies genernse to call wires and the identified dynamic response to the generator model under the same excitation, verifying equivalence results and obtaining an equivalence model. The invention identifies generator parameters by using the niche immune algorithm, thereby improving the overall convergence, the convergence speed and the species diversity of the traditional immune algorithm, having the characteator parameters by using the niche immune algorithm, thereby improving the overall convergence, the convergence speed and the species diversity of the traditional immune algorithm, having the characteristics of high equivalence speed and high precision, solving the problems of speed and precision of an estimated equivalence method and being suitable for on-line and real-time safety analysis of a pristics of high equivalence speed and high precision, solving the problems of speed and precision of an estimated equivalence method and being suitable for on-line and real-time safety analysis of a power system.ower system.