The present disclosure provides a battery high voltage sampling circuit and a battery management system. The battery high voltage sampling circuit includes a positive relay, a negative relay, a first positive sampling unit, a first negative sampling unit and a reference voltage terminal, wherein: a first terminal of the positive relay is connected to a positive electrode of a power battery pack to be detected, a first terminal of the negative relay is connected to a negative electrode of the power battery pack to be detected, and both of the first positive sampling unit and the first negative sampling unit are connected to the reference voltage terminal.