1. A head-up display device for a vehicle using augmented reality, comprising: a distance detector configured to detect a distance between a driver's vehicle and a front vehicle in front of the driver's vehicle to output distance information; a navigator configured to output a position of the driver's vehicle and information about a road on which the driver's vehicle drives, as driving information; and an image controller configured to calculate a transverse position of the front vehicle according to the distance information and the driving information, and generate image information corresponding to the front vehicle by using the transverse position, wherein the image controller corrects the transverse position according to whether any one of the driver's vehicle and the front vehicle enters a junction between a curved road and a straight road.