A vehicle power supply control device includes a main line unit of one system, branch line units, a vehicle power supply master, and an area power supply master. The main line unit of the one system is provided to a vehicle. Each of the branch line units branches from the main line unit of the one system. The vehicle power supply master includes a main battery that charges and discharges electric power. The area power supply master is connected to the main line unit of the one system through the branch line unit and is connected to a load unit that consumes electric power, and includes an area battery that charges and discharges electric power. The vehicle power supply master supplies electric power of the main battery to the area power supply master through the main line unit of the one system.