A communication apparatus for a vehicle according to an embodiment and a control method therefor are disclosed. The communication apparatus for a vehicle comprises: an antenna unit including a first antenna and a plurality of second antennas; a first switch for switching a first path to the first antenna and a second path to each of the plurality of second antennas; a second switch for switching a second path to any one of the plurality of second antennas; a length adjustment unit that is connected to the second path to the one second antenna connected to the second switch and adjusts the resonance length of the connected second antenna; and a communication control unit that generates a switching signal for connection to any one of the plurality of second antennas according to the state of the first antenna.