In this study, a fast simulation technique is proposed for analysis of power electronic circuits. After switching,these circuits behave like linear circuit, Therefore, it can be linear circuit analysis methods. In the simulation, capacitors and inductors are replaced by voltage and current sources, respectively, whose values are determined by their current and voltages in previous step. The method is based on solving a system of algebraical modified nodal equations at each integration step. The technique requires only DC analysis. The writing or solving time-differential equations or Laplace transform inverses aren't required. Thus, it causes the simulation to be fast one. It's used the linear circuit model for semiconductor devices. Simulation time is essentially the same as for linear, time-invariant circuit of the same complexity. Simulation algorithm is given and an example is included.