The time-variation and randomness of load in a power system is a big problem for the real-time or faster-than-real-time analysis of transient stability. A fast load modeling method for the real-time or faster-than-real-time transient stability analysis is presented. The principal idea of the method is“real-time identifying and real-time applying”. A strong tracking filter（STF） is used in identifying the key parameters of the load model in real-time. Then the identified parameters are instantly applied in the real-time transient stability analysis. Simulation results demonstrate that the method proposed can meet the need of real-time transient stability analysis in terms of not only accuracy but also the calculating speed.