The invention relates to a digital display direct current meter and a voltage sampling circuit thereof. The voltage sampling circuit comprises an input voltage division module, an input filtering module, an isolation amplifying module, a voltage regulating module and an output filtering module which are sequentially connected in series; a detected voltage is accessed to the input terminal of the input voltage division module, the output terminal of the output filtering module is connected with a processor of the digital display direct current meter; and the input filtering module comprises a common mode filter circuit and a secondary filter circuit, the input terminal of the common mode filter circuit is connected with the output terminal of the input voltage division module, the output terminal of the common mode filter circuit is connected with the input terminal of the secondary filter circuit, and the output terminal of the secondary filter circuit is connected with the input terminal of the isolation amplifying module. The voltage sampling circuit is mainly applied to a vehicle-mounted instrument, safety of the whole circuit can be improved, and an instantaneous high voltage can be prevented from damaging a rear-end circuit; meanwhile, an interference signal can be effectively filtered, and EMC and antijamming capability of the digital display direct current meter can be improved; and the problems of the digital display direct current meter that a measuring range is limited, the safety is low and the EMC and antijamming capability are poor are solved.