Because of nonlinear, strong coupling and immeasurable variables, induction motor parameter identification need solve complex nonlinear differential equations; it may lead to difficulties in the parameters identification process. A simplified complex-quantity model, which is expressed by straight axis and quadrature axis component of the voltage and current, is proposed for induction motor. Using step acceleration method, the parameters of the model are identified according to voltage and current transient data. This model simplifies the process of parameter identification by taking nonlinear characteristic of induction motor into account and avoiding solving the complex nonlinear differential equations. So the convergence of the algorithm and the accuracy of the results are ensured and the stability and efficiency of the identification process are improved. The examples are conducted under two kinds of motor control methods, and the simulation results show identifiability and high precision, which verify the correctness, effectiveness and practice of the model.