The invention relates to an extra-high voltage direct-current restart simulation optimization method. The method includes the following steps that: extra-high voltage direct-current mono-polar line fault restart actual measurement data are obtained, direct-current mono-polar fault line restart parameters and post-fault alternating current system key weak cross section response condition are determined; extra-high voltage direct-current mono-polar fault line restart is simulated based on the direct-current mono-polar fault line restart parameters, and post-fault alternating current system key weak cross section response condition after simulation is determined; whether the error value of a simulation results is larger than an error result minimum value is judged; and an extra-high voltage direct-current bipolar fault line restart time sequence is determined based on an extra-high voltage direct-current mono-polar fault line optimal restart time sequence. With the method adopted, the impact characteristic of the restart time sequence after an extra-high voltage direct-current fault, and extra-high voltage direct-current mono-polar/bipolar restart on an alternating current system can be accurately simulated. The extra-high voltage direct-current restart simulation optimization method has the advantages of simple and accurate calculation process and accurate results, and can be applied to the formulation of extra-high voltage direct-current mono-polar/bipolar restart strategies and safety and stability analysis of an alternating current/direct current hybrid power grid system.