The invention provides a phase-locked loop electromechanical transient simulation method and device considering dynamic characteristics. According to the method, a phase-locked loop output phase of each time node is determined first; when the time nodes are initial time nodes, according to the phase-locked loop output phase of each time node, active power and reactive power exchanged by a flexibledirect-current transmission system and an alternating-current system under the corresponding time nodes are calculated; and last, a phase-locked loop electromechanical transient simulation curve is output according to the active power and the reactive power exchanged by the flexible direct-current transmission system and the alternating-current system. Through the simulation method and device, the dynamic characteristics of a phase-locked loop are considered, and the simulation precision of an electromechanical transient system of the flexible direct-current transmission system is improved. According to the phase-locked loop electromechanical transient simulation method considering the dynamic characteristics, phase-locked loop electromechanical transient simulation is realized through closed-loop control, the thought is clear, and application is wide.