Electric energy meter capable of automatically adjusting liquid crystal contrast

The utility model relates to an electric energy meter capable of automatically adjusting liquid crystal contrast, in particular to the technical field of instruments and meters. The electric energy meter comprises a main power supply circuit, a standby power supply circuit, a control circuit and a segment code type liquid crystal. The main power supply circuit comprises an AC-DC conversion circuit, the input end of the AC-DC conversion circuit is connected with an AC voltage, and the output end of the AC-DC conversion circuit is connected to a target capacitor through a first diode and a current-limiting resistor; the output end of the AC-DC conversion circuit supplies power to the electric energy meter through a second diode. The standby power supply circuit comprises a sampling circuit; the target capacitor is connected to a sampling voltage pin of a processor in the control circuit through the sampling circuit; a contrast control pin of the processor is connected to a register control pin in the segment co