An X-ray apparatus capable of releasing a locked rotation of a wheel using a power supplied from an auxiliary battery of an X-ray detector when a body is discharged, and a control method thereof. A mobile X-ray apparatus includes a body including a body battery, a detector accommodator and a wheel, an X-ray source emits X-rays to an object, a detector battery connector provided on the body and connectable to a detector battery, a power supply circuit connected to the detector battery connector to form a first path in which a power is supplied from the body battery to the detector battery and a second path in which a power is supplied from the detector battery to the body, and a controller controls the power supply circuit to selectively form the first path and the second path.
