Abstract: Green and efficient new energy systems have been widely used in automobiles, trams, and smart buildings. To reduce the operating cost of DC microgrid of fuel cell (FC) tram, the paper proposed an energy management optimization method for FC tram DC microgrid system based on multiple- population firefly algorithm. The method introduced the operation cost model based on the initial cost, operation cost, and maintenance cost. Aiming at the model, a multiple- population firefly algorithm combining multiple-population genetic algorithm and firefly algorithm was established to optimize the state machine control strategy for FC tram. Under the three test cycles, the proposed method was compared with the state machine control strategy, the genetic algorithm-based strategy, the multiple-population genetic algorithm-based strategy, the particle swarm optimization-based strategy, and the firefly algorithm-based strategy. The results show that the proposed method can reasonably allocate the power output of the three energy sources and obtain the lowest operating cost.