A battery cooling device for a vehicle is provided. The device repeats phase changes of a refrigerant to cool a battery due to heat of vaporization when a liquid-state refrigerant is vaporized by thermally coming in contact with a battery heat source. The vaporized refrigerant is changed back into a liquid state by thermally coming in contact with a separate coolant. The effect of cooling all battery cells is maximized throughout the entire refrigerant channel for cooling a battery and the battery cells are cooled uniformly.