The invention provides a vehicle group control method that controls the traveling of a vehicle group including a plurality of vehicles. The vehicle group control method includes: a process of controlling vehicles in each of a plurality of small vehicle groups which are divided from the vehicle group and controlling the relative relationship between the vehicles in each small vehicle group using communication between the vehicles in the same small vehicle group; and a small vehicle group control process of controlling the relative relationship between the small vehicle groups using communication between representative vehicles in the small vehicle groups.