A device for controlling alcohol interlock according to an embodiment of the present disclosure includes a sensor for obtaining position information and breath information of a fellow passenger, and a controller that determines whether a blood alcohol concentration of the fellow passenger is measured based on the position information and the breath information of the fellow passenger, and determines whether to re-measure a blood alcohol concentration based on the determination result. Thus, the device may prevent surrogate measurement of the fellow passenger, so that a driver's own blood alcohol concentration may be measured accurately, and drunk driving of a driver may be fundamentally prevented.