With the assessment of single-phase microgrids (MGs), three-phase/single-phase (TP/SP) hybrid multi-microgrids (MMGs) are emerging, provided with more complex architecture. This paper deals with the black-start problem for TP/SP MMGs in islanded mode caused by an unscheduled breakdown from the main grid. The three-phase units, such as energy storage systems (ESSs), photovoltaic (PV) systems, and loads, are virtualized as single-phase units to simplify the computation complexity. Then, the fast particle swarm optimization (FPSO) algorithm applicable to the mixed integer programming problem is introduced to solve the multi-objective restoration problem. Based on the ultimate states given by FPSO, an optimum restoration path is found through the generalized minimum spanning tree (GMST) algorithm based on the improved Prim algorithm. Simulation results are presented to demonstrate the effectiveness of the proposed strategy.