The present invention provides a method for determining a target of alcohol test, including: determining whether a motor vehicle satisfies a preset condition; and determining, as a target vehicle, a motor vehicle that satisfies at least one preset condition. The preset condition comprises at least one of: a parking duration in an area, in which a distance from a place selling alcoholic drinks does not exceed a predetermined distance, has a value within a predetermined range; alcohol content in a body of a driver of the motor vehicle exceeds a predetermined value; and schedule of a driver of the motor vehicle on that driving day comprises having a meal and/or a dinner party. The present invention further provides a driving safety device, a server and a driving safety system.