This application provides a control circuit apparatus of a battery system and a battery management system, and is applied to the field of battery equalization technologies. The control circuit apparatus in this application includes a switch matrix network unit, a first equalization unit, and a second equalization unit. The switch matrix network unit is configured to: form a loop between m battery units in the battery system and the first equalization unit, and form a loop between the m battery units in the battery system and the second equalization unit. The first equalization unit discharges a high-voltage battery unit through a resistor unit, and the second equalization unit charges a low-voltage battery unit through a transformer.