The invention discloses a high-voltage isolation system applied to an energy storage device of a tram. The high-voltage isolation system applied to the energy storage device of the tram comprises a bidirectional DC/DC converter and a pre-charging circuit; the bidirectional DC/DC converter is placed inside the tram, one end of the bidirectional DC/DC converter is connected witha high-voltage bus,and the other end of the bidirectional DC/DC converter is connected with the energy storage device through the pre-charging circuit; and the pre-charging circuit is disconnected during train sleep maintenance to cut off a power-on loop between the high-voltage bus and the energy storage device, so that the high-voltage bus is in an unpowered state.According to thehigh-voltage isolation system applied to the energy storage device of the tram, the tram does not need to be discharged before topclimbingoperation, the preparation time of the topclimbingoperation can be greatly shortened, and the efficiency of tram maintenance operation is improved; waste of residual electricity in the energy storage device is avoided, and the arrangement number of charging and discharging devices of the tram in avehicle section isdecreased, and the cost is lowered; and under the premise of ensuring the personal safety of maintenance personnel, the efficiency of tram operation and maintenance is significantlyimproved, the operating cost is lowered, and significant economic benefits are obtained.