An algorithm for simulating switched networks based on nonlinear iterative method is presented. Using this algorithm, an algebra equation is transformed into an ordinary differential equation (ODE), and then the numerical method is used to obtain the steady state of the ODE. The steady state is just the root of the algebra equation. The commutation time can be evaluated precisely and exponential matrix can be requested by precise computation for transient analysis. Compared to the conventional approaches for algebra equation, the nonlinear iterative method is provided with wide convergence range, high precision, high efficient compare with other iterative methods and it has no need of using derivative in the course of iterative. The simulation results to illustrative example indicate the correctness and efficiency of the presented algorithm. It is a new thought to simulate switched power converters.