An antenna device with an adaptive polarization switching function, the antenna device including an antenna array comprising a first linear polarization antenna and a second linear polarization antenna, the first linear polarization antenna and the second linear polarization antenna having polarization directions orthogonal to each other, and a feeding unit comprising an input terminal for receiving a transmission signal, a first output terminal coupled to the first linear polarization antenna, and a second output terminal coupled to the second linear polarization antenna, wherein the feeding unit distributes energy of the transmission signal to the first output terminal and the second output terminal according to a control signal so as to generate feeding signals of the first linear polarization antenna and the second linear polarization antenna and to make the feeding signals have a phase difference.