The invention discloses an acoustic magnetic anti-theft system and an antenna structure thereof. The antenna structure comprises an antenna body and a wave absorbing layer made of a wave absorbing material and used for absorbing electromagnetic wave signals in a first frequency range, wherein the antenna body is provided with a first surface for transmitting and/or receiving the electromagnetic wave signals and a second surface for facing an electromagnetic interference source, the first surface and the second surface are located on different sides of the antenna body, and the second surface of the antenna body is provided with a wave absorbing layer; the first frequency range is consistent with an operating frequency range of the antenna body and coincides with the electromagnetic interference frequency range of the electromagnetic interference source. It is ensured that the acoustic magnetic anti-theft system does not remarkably decrease the detection distance of an acoustic magneticsoft label, and accordingly the matched use of the acoustic magnetic anti-theft system for the acoustic magnetic soft label is facilitated.