The invention discloses an electromagnetic transient simulation method for a power electronic switch, and the method comprises the steps: carrying out the automatic classification of power electronicswitch equipment, and carrying out the unified integration of strong correlation switch equipment; searching the action condition of the power electronic switch, determining the action moment of the switch, and obtaining a changed admittance matrix; calculating an injection current source used in the next simulation time step, and if the switching action does not occur, calculating the injection current source by using the calculation result of the previous simulation time step and calculating the node voltage and the branch current of the next simulation time step by using the updated injection current source; if a switching action occurs, calculating a new injection current source by adopting a method of eliminating numerical oscillation through twice iterative calculations; node voltageand branch current of the next simulation time step are calculated, numerical oscillation is eliminated by adopting a power electronic electromagnetic transient simulation method based on iteration.The problem of low simulation accuracy of a synchronous switch and a multi-switch is solved by utilizing a combined power electronic switch mode and a multi-switch action search method.