For reducing the metro operation cost, according to the energy consumption during the trial operation of Changsha metro line 2, the characteristics of energy consumption for propulsion, motive and lighting devices was analyzed, and the existing energy saving technical and measures were described. The effect of energy saving measures, such as regenerative braking of train, optimal control of air conditioning in station etc., were affirmed in actual operation, at the same time, the next energy saving scheme such as the regenerative electric energy absorption and utilization system was introduced.