Disclosed is an electric vehicle battery attaching/detaching device including a battery mounting unit formed on an electric vehicle to detachably mount a battery and provided with a connector pin module adapted to be lifted/lowered by a lifting/lowering means; a loader having a plurality of battery stands, each battery stand being adapted to detachably mount a fully-charged battery to be exchanged with the battery mounted on the battery mounting unit; and a battery attaching/detaching unit adapted to move along X-axis, Y-axis, and Z-axis between the battery mounting unit and the battery stand by means of a movement device, detach a battery mounted on the battery mounting unit or the battery stand, and exchange/mount the battery on the battery stand or the battery mounting unit.