The present invention provides a signal response method, a device and a system. The method comprises the steps of receiving a carrier signal of 125 KHz in frequency by an antenna of 13.56 MHz in resonant frequency; amplifying the carrier signal and subjecting the amplified signal to analog-to-digital conversion to obtain a digital signal; according to the digital signal, acquiring the signal characteristics of the carrier signal, wherein the signal characteristics at least comprise the frequency and the phase; encoding response data in the frequency form to obtain an encoded signal, determining the initial phase of the to-be-outputted encoded signal according to the phase, outputting the encoded signal through the antenna, and superimposing the encoded signal and the carrier signal at the same phase. According to the technical scheme of the signal response method, the device and the system, signals of 125 KHz in frequency can be received and sent by the antenna of 13.56 MHz in resonant frequency, wherein the antenna is smaller in volume. Therefore, the miniaturization requirements of equipment are realized.