Provided are a method and a device for assisting with driving of a vehicle, the method including sensing an ambient environment of location of a vehicle by using one or more sensors mounted on or in the vehicle; obtaining sensing information about the ambient environment based on the sensing of the ambient environment; comparing map information stored in the vehicle with the obtained sensing information; determining a map reliability of the map information based on a result of the comparing; and controlling the driving of the vehicle based on the determined map reliability.