A bicycle carrier system for a vehicle may include guide rails disposed at a lower portion of a bumper back beam, a carrier part provided with a panel part and side portions extending from both sides of the panel part to the guide rails to move along the guide rails, a first driving part connected to the guide rails to move the carrier part along the guide rails, an expansion support part installed between the side portions of the carrier part to support a loaded bicycle, a second driving part installed at the carrier part to be connected to the expansion support part and expandably deploy the expansion support part, and a control unit controlling the first and second driving parts and sequentially controlling the first and second driving parts to draw out the carrier part and then performing an expansion deployment operation of the expansion support part.