Detection antenna system for intermediate frequency radio frequency identification card and detection method

The invention provides a detection antenna system for an intermediate frequency radio frequency identification card and a detection method. The system comprises a time sequence communication device, asignal processing device, a circuit adjusting device and signal transmitting and receiving antenna devices, wherein the time sequence communication device is used for sending a switch control signaland a modulation signal to the signal processing device according to a time sequence, and receiving identification card return data according to the time sequence; the signal processing device is usedfor generating a transmitting power signal according to the modulation signal, receiving an identification card return signal and demodulating the identification card return signal into return data to be transmitted to the time sequence communication device; the circuit adjusting device is used for carrying out impedance adjustment and fine matching on circuits between the signal processing device and the signal transmitti