The invention discloses an electromechanical transient model of a distributed power flow controller and an electromechanical transient simulation method. The electromechanical transient model comprises a standard test system, a DPFC (Distributed Power Flow Controller) series connection side user-defined model and a DPFC parallel connection side user-defined model. When power flow analysis is performed on an electric power system according to a working principle of the distributed power flow controller, injection current of the distributed power flow controller for an electric power network interface node is adjusted by applying an injection current method idea considering three times of harmonic dynamic energy exchange inside, and a function of controlling line power flow and bus voltage is realized. According to the invention, a mathematical model of equivalent current injected into nodes at two ends of a line at series and parallel connection sides of the distributed power flow controller considering three times of harmonic dynamic energy exchange inside is derived, and the mathematical model is applicable to the simulation process of electromechanical transient analysis for the electric power system, thereby providing a method for further studying the performance and characteristics of the DPFC, and providing a model basis for performance analysis for the DPFC.