An output voltage compensation charger circuit comprises an AC/DC circuit, an output interface, an charging control circuit and a compensation circuit, wherein, the AC/DC circuit converts DC power into an AC power, and the AC power charges up the battery through the output interface after boosted through the transformer; the charging control circuit is used to increase the voltage of the output interface so as to accelerate charging the battery, and the voltage lost in the circuit compensation circuit is compensated by the compensation circuit; thus, the energy loss caused by the circuit internal resistance can be overcome, maintaining the charging effect of the charger.