A vehicle power supply control device includes a vehicle power supply master connected at one end of a single-system trunk line unit and including a main battery charged with power and discharging power, a plurality of area power supply masters connected with the single-system trunk line unit through branch line units and connected with load units consuming power, a first supply path supplying power from the vehicle power supply master to the area power supply masters through the single-system trunk line unit, a second supply path different from the first supply path, and an external power supplying unit provided outside the area power supply masters and supplying power to the area power supply masters through the second supply path.